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Marfan syndrome: Getting to the root of the problem
Franken, Romy
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Franken, R. (2016). Marfan syndrome: Getting to the root of the problem
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Download date: 19 Jun 2017
5
Adapted from:
Diagnosis and Genetics of Marfan
syndrome
Expert Opin Orphan Drugs 2014;2:1-14
Romy Franken
Thomas J. Heesterbeek
Vivian de Waard
Aeilko H. Zwinderman
Gerard Pals
Barbara J.M. Mulder
Maarten Groenink
Abstract
Introduction: Marfan syndrome (MFS) is a connective tissue disorder with highly variable features in cardiovascular, ocular and skeletal systems. MFS is generally caused by
one of the 2900+ described different genetic mutations in FBN1 .
Areas covered: By revising the Ghent criteria in 2010, more weight has been given to
genetic testing in the diagnosis of MFS. We provide an overview of correlations between
different mutation-types and clinical MFS features by using the Universal Mutation
Database (UMD).
Expert opinion: In this study we classified FBN1 mutations based on their action on
DNA level and we found the following genotype-phenotype correlations: 1) cysteine
mutations are associated with ectopia lentis; 2) introduction of a cysteine leads to less
severe involvement of cardiovascular and skeletal systems; 3) whole gene deletions and
premature termination codon (PTC) mutations are associated with increased skeletal
and cardiovascular involvement, but lower prevalence of ectopia lentis; and 4) intronic
mutations lead to MFS by exon skipping, small insertions/deletions and PTC mutations.
Classification based on mutation-effect at protein level (reduced versus truncated/
deformed fibrillin-1) may partly explain genotype-phenotype association and warrants
further investigation for individualized prognosis and treatment.
Conclusion: Genotype-phenotype correlations can be identified in MFS and may be
explained by their mutation-effect on protein level.
68
Chapter 5: Diagnosis and genetics
Introduction
Marfan syndrome (MFS) is a multi-system connective tissue disorder with a prevalence
of 1 per 5000 individuals, generally caused by mutations in the gene encoding for fibrillin-1 (FBN1) and inherited in an autosomal dominant manner.1 FBN1 mutations induce
abnormal or deficient fibrillin-1 protein synthesis, affecting the structural integrity of the
extracellular matrix in a multitude of organs. The most feared and often lethal complication is aortic dissection, which mostly occurs after gradual dilation of the aorta.2 Aortic
dilation is caused by degenerative features in the aortic wall, which are associated with
enhanced release of transforming growth factor-β (TGF-β).3,4 Aortic dilation, especially
of the aortic root, is present in the vast majority of MFS patients.5-7 The introduction
of prophylactic aortic root replacement (generally at an aortic diameter of 50 mm) has
led to increased life expectancy.8 In addition, several pharmacological drugs have been
reported to slow down aortic dilation in patients with MFS.9 Diagnosis is based on major
and minor criteria, comprising family history of MFS, mutation analysis and specific
phenotypic characteristics, including ectopia lentis, dural ectasia, skeletal features, and
aortic dilation or dissection (Table 1).10-13 These criteria (the so called ‘Ghent’ criteria)
have been revised in 2010 by a panel of experts in the field of MFS.
In this review, we will focus on the increased importance of genetic testing as stated
in the revised Ghent criteria for diagnosis of MFS. Furthermore, we will provide 1) an
overview of different mutation-types based on their effect on RNA or protein level and
2) correlations between mutation-subtypes and clinical MFS features.
Table 1. Possible combinations of major criteria leading to Marfan syndrome
FH
Ao
EL
*
*
*
Syst
FBNc
*
*
*
*
*
*
*
*
*
FBNa
*
*
Abbreviations: Ao: aortic dilatation (Z≥2) or aortic dissection, EL: ectopia lentis,
FBNc: FBN1 mutation, FBNa: FBN1 mutation associated with aortic pathology,
FH: family member with Marfan syndrome, Syst: systemic score ≥ 7 out of 20 points
Each line represent a possible combination leading to Marfan syndrome
69
The history of diagnosing Marfan syndrome
Antoine-Bernard Marfan was the first to describe a five-year-old patient with long
slender fingers and other skeletal abnormalities in 1896.14 After this initial delineation,
other pleiotropic and phenotypic features of MFS were recognised by Victor McKusick.15
Finally, the Berlin nosology was formulated in 1986; the first guidelines for the clinical
diagnosis of MFS.16 However, some pitfalls including overdiagnosis of family members
forced experts in the field to develop a new diagnostic guideline published as ‘the Ghent criteria’ in 1996.17 The Ghent criteria made use of a classification for the different
clinical features, which were divided into major criteria with high diagnostic specificity
and minor criteria. The presence of a major criterion in two different organ systems and
a minor criterion in a third organ system were required to fulfil the diagnosis of MFS.17
A major breakthrough in understanding the pathophysiology of MFS was the discovery of the FBN1 gene on the long arm of chromosome 15 in 1991.18 Mutations in this
gene were shown to result in MFS in a considerable number of patients. To date, FBN1
mutations are found in approximately 90% of patients. Later, other gene mutations leading to MFS-like disease were discovered, such as mutations in the TGFBR1 and TGFBR2
genes, now considered to compose a specific entity known as Loeys-Dietz Syndrome.19
A revision of the Ghent criteria has been published in 2010.20 These revised guidelines
can be considered as a simplification of previous guidelines by giving more weight to
aortic root dilation, FBN1 mutation analysis and ectopia lentis.20 Criteria regarding less
specific manifestations of MFS were removed or became less influential in the diagnostic
evaluation. Diagnosis of MFS in patients without affected family members can now be
established when a patient has two major criteria: 1) aortic root dilation (Z-score ≥2); 2)
ectopia lentis; 3) skeletal score ≥ 7 points (out of 20); and 4) pathogenic FBN1 mutation
leading to aortic dilation. In patients with a MFS affected family member, only one of the
four major criteria is needed to establish diagnosis of MFS (Table 1).
Reconsidering the child originally presented by Antoine Marfan, the diagnostic value
of mutation analysis becomes clear. This child was probably not affected by MFS, but by
congenital contractural arachnodactily, a connective tissue disorder caused by a FBN2
mutation. These patients have more pronounced skeletal abnormalities, but rarely have
aortic root dilation – the main cause of morbidity and mortality in MFS.21
The FBN1 gene
Patients with MFS have a highly variable phenotype, vary in age of onset of manifestations, and vary in responsiveness to medical treatment, both between different families
as within families sharing the same mutation.22,23 Currently, more than 2900 different
70
Chapter 5: Diagnosis and genetics
mutations in the FBN1 gene have been described, and over 90% of these mutations are
unique to an individual or family.24
The FBN1 gene is located on the long arm of chromosome 15 at 15q15-q21.1. It is
a large gene fragmented in 65 exons, including 47 epidermal growth factor (EGF)-like
domains, each containing six conserved cysteine amino acids, of which 43 EGF-domains
are known to bind calcium.25 The calcium binding (cb) potential is important for the
protection against proteolytic activity and for correct folding of the fibrillin-1 protein.
Furthermore, the FBN1 gene contains seven domains that bear homology to latent
TGF-β binding proteins (TB-domains)26, each containing eight cysteines.26 In addition,
there are two hybrid domains (the HB-domains) with homology to both EGF- and TBdomains.27 In between the 65 exons encoding the fibrillin-1 protein, the FBN1 gene also
contains introns; these introns are normally removed by RNA splicing to generate the
mature RNA that will be translated. Mutations leading to MFS comprise deletions of (a
part of ) the FBN1 gene, or minor mutations which can be located in all EGF-like domains,
the TB- and HB-domains, as well as in the introns.
Location of the FBN1 mutations is of great importance. For example, FBN1 mutations
located between exon 24-32 often lead to a neonatal form of MFS – a severe form of MFS
usually diagnosed at birth, with lethal cardiorespiratory failure during the first weeks of
life.28-31 Furthermore, mutations in the FBN1 gene may also lead to stiff skin syndrome
located in exon 37, acromicric dysplasia located in exon 41-42, and Shprintzen-Goldberg
craniosynostosis syndrome located in exon 29.31-34 Thus, the position of the FBN1 mutation determines the resulting phenotype, which is not exclusively MFS. In this review we
give an overview of MFS phenotypes correlated to the different FBN1 mutations.
Overview of literature
We reviewed all articles reported in the Universal Mutation Database (UMD). We included all patients from the UMD, registered until March 2014, with (partially) described
phenotypes. 35 We carefully monitored duplicate mutations to avoid the description of a
patient more than once. We scored the following clinical features: gender, age, cardiac
involvement (including aortic aneurysm or aortic dissection as ‘major’, and mitral valve
prolapse as ‘minor’), ocular involvement (including ectopia lentis as ‘major’, or one of
the minor ocular features as ‘minor’) and skeletal involvement. The definition of ‘major
involvement of the skeletal system’ in this manuscript comprised patients with major
skeletal involvement according to the Ghent criteria of 1996, or/and patients with ≥ 7
points according to the Ghent criteria of 2010. Minor skeletal involvement was defined
as at least one of the known skeletal features present in MFS.
71
In total, we reviewed 143 articles and included 1511 patients with a pathogenic FBN1
mutation with (partially) known MFS phenotype. In these patients a missense mutation
was present in 846 patients (56%) in whom a cysteine amino acid was involved in 555
patients (66%). A premature termination codon (PTC) was present in 442 patients (29%),
a deletion or insertion of (a part of ) the FBN1 gene was present in 116 patients (8%)
and an intron mutation was present in 161 patients (11%). Finally, two patients had a
homozygous mutation and 7 patients carried two different FBN1 mutations.
Mean age of the total cohort was 30 years, with 48% females and 80% prevalence
of cardiac involvement (aortic aneurysm 71%, aortic dissection 22%, and mitral valve
prolapse 51%). Furthermore, ectopia lentis was present in 52% of the patients and 29%
had major involvement of the skeletal system (Table 2). All test were performed by twosided Fisher’s exacts tests.
Different types of FBN1 mutations
Cysteine mutation
A cysteine mutation is a missense mutation substituting the amino acid cysteine for
another amino acid, or introducing a cysteine at a new position. A cysteine substitution
is the most common mutation type among all pathogenic FBN1 mutations. Cysteines are
essential in forming disulphide bridges to establish the ternary structure of a protein.
In fibrillin-1 there are more than 360 cysteines present, which is an exceptional large
number for a single protein. The substitution of a cysteine by glycine is responsible for
the development of a MFS phenotype in a well-known MFS mouse model (p.C1039G).36
Most cysteine substitutions involve a cb-EGF-like domain; this calcium-binding property is important for correct folding of fibrillin-1. The cb-EGF-like domains are highly
conserved and contain 6 cysteine amino acids per domain, forming three disulphide
bridges.37 Cysteine substitutions disrupt one of these three disulphide bridges, which
has a predictable detrimental effect on the domain itself as well as on the cb-property
of the domain.
We affirmed that a correlation between cysteine mutations and increased prevalence
of ectopia lentis exists, compared to the total cohort of patients with a (partially)
known phenotype and a pathological FBN1 mutation (71% versus 52%, p<0.001). We
summarized these results and other clinical features in Table 2.32,34,38-85 Interestingly,
there was a difference in MFS phenotype between cysteine substitutions and cysteine
introductions, with a higher prevalence of aortic aneurysms and mitral valve prolapse in
patients with a cysteine substitution compared to patients with a cysteine introduction
(aneurysm: 78% versus 52%, p<0.001; mitral valve prolapse: 61% versus 27%, p<0.001,
respectively). As noted previously, it seems that the disappearance of a conserved cys72
Chapter 5: Diagnosis and genetics
teine leads to a more severe cardiovascular involvement compared to the introduction
of a new cysteine.86
Non-cysteine missense mutations
Another large group of FBN1 mutations comprise missense mutations substituting an
amino acid by another amino acid (without involvement of a cysteine). Interestingly,
patients with a non-cysteine missense mutation had a more severely affected cardiovascular system (aneurysms: 65% versus 52%, p=0.031; mitral valve prolapse: 44% versus
27%, p=0.023), as well as skeletal system (skeletal involvement 86% versus 63%, p<0.001),
compared to patients with a missense mutation where a cysteine was introduced.
However, the non-cysteine missense group did not significantly differ from the cysteine
substitution group (Table 2).18,32-34,37-40,42,44,46-48,50,51,59,60,64,66,67,74,75,78,80-82,85,87-109 We did not find
an explanation for these unexpected results. Missense FBN1 mutations are traditionally
thought to cause a ‘dominant negative effect’, leading to disturbed folding of the protein
or disturbed interactions with fibrillin-1 or other extracellular matrix proteins, hence a
disorganized tissue matrix. Apparently, there seems to be more distinction between
these different missense mutation groups, which deserves further investigation.
Intron mutations and other mutations leading to minor in frame deletions or
insertions
In approximately 90% of the MFS patients a FBN1 mutation is found. Recently, Gillis
E et al. suggested that deep intronic mutations may cause MFS in patients without a
Table 2. Missense mutations leading to deformed fibrillin-1 protein
Overall
n = 1511
Gender (female)
Age (years)
Cardiac involvement
Total C mutation¹
n = 555
From C to #¹
n=398
From # to C¹
n=157
From # to # ²
n=298
381 (48%)
151 / 311 (49%)
113 / 228 (50%)
38 / 83 (46%)
74 / 163 (45%)
30 ± 19
29 ± 18 (n=343)
27 ± 16 (n=255)
35 ± 20 (n=88)
31 ± 18 (n=165)
1050 / 1315 (80%) 351 / 459 (76%)+
286 / 347 (82%) 65 / 112 (58%)** 187 / 257 (73%)*
Aortic aneurysm
817 / 1146 (71%)
279 / 392 (71%)
231 / 299 (77%)*
Aortic dissection
134 / 619 (22%)
42 / 220 (19%)
36 / 169 (21%)
Mitral valve prolapse
452 / 885 (51%)
165 / 324 (51%)
139 / 233 (59%)*
26 / 91 (29%)** 74 / 170 (44%)+
389 / 477 (82%)
286 / 343 (83%)
103 / 134 (77%) 162 / 231 (70%)
Ocular involvement
875 / 1277 (69%)
Ectopia Lentis
661 / 1277 (52%)
Minor involvement
Skeletal involvement
835 / 1277 (65%)
48 / 93 (52%)** 143 / 219 (65%)+
6 / 51 (12%)
19 / 98 (19%)
340 / 477 (71%)** 248 / 343 (72%)** 92 / 134 (69%)** 123 / 231 (53%)
49 / 477 (10%)
1274 / 1511 (84%) 436 / 555 (79%)**
38 / 343 (11%)
11 / 134 (8%)
39 / 231 (17%)
337 / 398 (85%) 99 / 157 (63%)** 255 / 298 (86%)
Major involvement
439 / 1511 (29%)
131 / 555 (24%)
109 / 398 (27%)
22 / 157 (14%)
70 / 298 (24%)
Minor involvement
835 / 1511 (55%)
305 / 555 (55%)
228 / 398 (57%)
77 / 157 (49%)
185 / 298 (62%)
Fisher’s test demonstrated significant differences between the total cohort and subgroups marked with a symbol.
Abbreviations: C = cysteine amino acid, #: amino acid other than cysteine, + = p<0.05, * = p<0.01, ** = p<0.001
73
discovered pathogenic FBN1 mutation upon exon sequencing.110 Introns are normally
removed by RNA splicing, however intron mutations leading to MFS were present in
8% of the patients with a known MFS phenotype. These intron mutations may lead to
splice site disturbances and subsequently exon skipping or activation of a cryptic splice
site causing partial exon deletion or a (partial) intron insertion.110 In the UMD, an intron
mutation was found in 161 patients, but the mutation-effect was not tested in 85 patients (53%). In patients with an intronic mutation with a confirmed effect, the mutation
led to exon skipping (n=29, 38%), in frame deletion of a part of the exon (n=22, 29%), a
frameshift leading to a PTC (n=22, 29%), and in 3 patients it resulted in a small in frame
insertion (4%). The intron mutations leading to PTC are described in paragraph 5.5.
In total, 96 patients had a mutation resulting in a minor in frame deletion or insertion, of whom 55 patients had one exon deletion, 14 patients had less than one exon
deletion, 14 patients had more than one exon deletion, and in 13 patients the mutation
resulted in a minor in frame insertion.
Minor in frame deletion or insertions in exons, leading to altered fibrillin-1 protein
may also be caused by deletion of a nucleotide(s) (n=25), insertion/duplication of
a nucleotide(s) (n=9), missense mutation (n=1), or an unknown cause (n=7). There
were no significant differences in cardiovascular and systemic involvement, between
the patients with a mutation leading to at least 1 exon skipping, in frame deletion or
insertion, and intron mutations with unknown effect. Remarkably, patients with a small
in-frame deletion or insertion had a more severely affected ocular system compared to
patients with at least 1 exon deletion (Fisher exact tests: ectopia lentis: 85% versus 49%,
p=0.003). In Table 3, we described the phenotypes of patients with a deletion of one
or more exons, and the combination of minor deletion or minor insertion, and intron
mutations with unknown effect.27,29,32,38-40,42,46,47,50,51,57,59,64,66-67,74,82,84,111-129
Whole gene deletions, deletion of the exon 1 or exon 65
Besides mutations leading to deformed fibrillin-1, another type of mutation exists, leading to a reduced amount of normal fibrillin-1 protein. This condition is known as ‘haploinsufficiency’. In the minority of these mutations, deletion of the entire gene on one
allele is the cause of MFS. In MFS mice with a centrally deleted FBN1 allele (Fbn1mg∆/mg∆),
an excessive amount of active TGF-β is liberated from the matrix, which is considered to
be the cause of the clinical MFS manifestations in this MFS mouse model.4 It is currently
unknown whether excessive TGF-β signalling is also the cause of the MFS phenotype in
humans with an allelic deletion of the FBN1 gene. Haploinsufficiency, due to deletion of
the whole gene has been shown to result in a great variety of MFS manifestations, from
mild to severe.87,130-132 In addition to whole gene deletions, no transcript will be produced
when at least the first exon is deleted, sometimes accompanied by a deletion upstream
of FBN1, deleting also the regulatory and promoter regions of FBN1. In addition, deletion
74
Chapter 5: Diagnosis and genetics
Table 3. Mutations in introns, small insertions and deletions
Overall
n = 1511
Gender (female)
≥ 1 Exon del ¹
n=69
Inframe del/ins²
n=27
Intron, unknown³
n = 85
381 (48%)
24 / 51 (53%)
7 / 11 (64%)
20 / 37 (54%)
30 ± 19
27 ± 16 (n=39)
43 ± 67 (n=16)
25 ± 14 (n=61)
Cardiac involvement
1050 / 1315 (80%)
48 / 62 (77%)
17 / 22 (77%)
65 / 74 (88%)
Aortic aneurysm
817 / 1146 (71%)
39 / 54 (72%)
12 / 20 (60%)*
51 / 66 (77%)
Aortic dissection
134 / 619 (22%)
1 / 15 (7%)
2 / 9 (22%)
9 / 38 (24%)
Mitral valve prolapse
452 / 885 (51%)
22 / 47 (47%)
10 /16 (63%)
20 / 41 (49%)
Age (years)
Ocular involvement
875 / 1277 (69%)
28 / 57 (49%)
17 / 20 (85%)
51 / 72 (71%)
Ectopia Lentis
661 / 1277 (52%)
20 / 57 (35%)*
14 / 20 (70%)*
40 / 72 (56%)
Minor involvement
835 / 1277 (65%)
15 / 45 (33%)
6 / 38 (16%)
11 / 72 (15%)
Skeletal involvement
1274 / 1511 (84%)
55 / 69 (80%)
22 / 27 (81%)
74 / 85 (87%)
Major involvement
439 / 1511 (29%)
13 / 69 (19%)
5 / 27 (19%)
27 / 85 (32%)
Minor involvement
835 / 1511 (55%)
42 / 69 (61%)
17 / 27 (63%)
47 / 85 (55%)
Fisher’s test demonstrated significant differences between the total cohort and subgroups marked with a
symbol.
Abbreviations: del: deletion, ins: insertion, * = p<0.01
of the last exon (exon 65) will result in extended transcription due to the disappearance
of the termination codon, and the abnormal protein will be degraded subsequently.
There was one patient with a deletion of exon 65 in the database, revealing mainly eye
and skeletal symptoms, but no cardiovascular involvement (Table 4). Patients with a
whole gene deletion had significantly lower prevalence of ectopia lentis compared to
the total cohort (Fisher’s exact test: 28% versus 52%, p=0.006) and increased skeletal involvement (100% versus 84%, p=0.049). We summarized the clinical features of patients
with deletions of the whole FBN1 gene or deletions of at least the first exon in Table 4.
Large differences were seen between studies, possibly caused by extended deletions
beyond the FBN1 gene, which suggests that the function of genes upstream of the FBN1
gene on chromosome 15, including SLC24A5, MYEF2, CTXN2, SLC12A1 and DUT may be
involved in these phenotypes as well. In conclusion, haploinsufficiency results in a high
prevalence of cardiovascular involvement (95%), and a 100% involvement of the skeletal
system (Table 4). 66,87,130,133,134
Premature Termination Codon mutations
In DNA, triplets of nucleotides (codon), encode for amino acids. From the generated
mRNA, translation starts at the start codon and stops after passing the termination
codon (nucleotide sequence UAG, UAA or UGA). In patients with mutations leading to
a PTC, a novel termination codon is built into the transcribed mRNA, which will overrule the ‘normal’ termination codon and thus terminates the translation prematurely. In
MFS, 29% of the FBN1 mutations in the database were PTC mutations. PTCs were caused
75
by 1) nonsense mutations and 2) frameshift mutations. Nonsense mutations are point
mutations directly leading to a novel termination codon. Deletions or insertions of one
or more nucleotides (not a multiple of three) change the reading frame, and introduce
novel termination codons. In addition, intron mutations sometimes lead to a PTC.
Schrijver, et al., revealed by FBN1 mRNA quantitation that mutant transcript levels were
decreased, which suggests that mutant mRNA is preferentially degraded by a nonsensemediated mRNA decay mechanism. 135 In Table 4 we summarized the clinical features
of patients with a PTC and known phenotype. In line with the results of whole gene
deletions, Fisher’s exact tests revealed that MFS patients with PTCs led more often to
major involvement of the skeletal system (82% versus 65%, p<0.001, respectively), but
less frequently to ectopia lentis (29% versus 41%, p<0.001, respectively) compared to
the total cohort, suggesting that most PTCs result in a haploinsufficient MFS phenotype.
29,34,39,40,42,47,51,58,59,61,64,66,67,74,75,78,80-82,89,94,122-124,126,136-154
Homozygous mutations and patients carrying two different FBN1 mutations
MFS is mostly an autosomal dominant inheritable connective tissue disorder. However,
index cases with a confirmed homozygous mutation in the FBN1 gene exist, and thus
MFS rarely inherit recessively. In 2007 de Vries et al. were the first to confirm a recessive mutation in the FBN1 gene. The homozygous mutations in two sibs, affected with
classical MFS, were located in exon 11 of the FBN1 gene (c.1453C>T, p.R485C). All four
blood-related parents, with mild signs of MFS, were heterozygous for the c.1453C>T
FBN1 mutation. One other sibling, without clinical features of MFS was tested positive
as carrier of the mutation.155 In 2010 another recessive family was described, in whom a
heterozygous mutation did not exert an important effect, but the homozygous patient
was affected with the classical clinical MFS phenotype.101
A second rare phenomenon within the spectrum of MFS is the presence of two
different FBN1 mutations in one individual. In total 7 patients had two different FBN1
mutations, with in general a more severely affected MFS phenotype (Table 4). For example, one child carried the maternal intronic mutation (c.2728+3A>G) in combination
with the paternal (p.Q454P) mutation, and demonstrated a more severe cardiovascular
phenotype compared to his brother with only the maternal mutation. The father only
showed mild aortic dilation, while the mother showed classical MFS.39
Conclusion
In conclusion, MFS is mostly an autosomal dominant heritable connective tissue disorder
with a heterogeneous expression of clinical features ranging from mild skeletal abnormalities to fatal aortic dissections. Associations between different genotypic mutation76
Chapter 5: Diagnosis and genetics
Table 4. Mutations leading to reduced fibrillin-1 protein and patients with two different FBN1 mutations
Overall
n = 1511
Gender (female)
381 (48%)
9 / 16 (56%)
91 / 193 (47%)
1 / 2 (50%)
30 ± 19
23 ± 14 (n=19)
31 ± 15 (n=326)
33 ± 7 (n=3)
Cardiac involvement
1050 / 1315 (80%)
18 / 19 (95%)
351/406 (86%)**
5 / 6 (83%)
Aortic aneurysm
817 / 1146 (71%)
16 / 18 (89%)
267/366 (73%)
5 / 6 (83%)
Aortic dissection
134 / 619 (22%)
0/18 (0%)#
60/211 (28%)*
0 / 5 (0%)
Mitral valve prolapse
452 / 885 (51%)
11 / 19 (58%)
144/257 (56%)+
2 / 5 (40%)
Ocular involvement
875 / 1277 (69%)
10 / 18 (56%)
206/389 (53%)
6 / 7 (86%)
Ectopia Lentis
661 / 1277 (52%)
5 / 18 (28%)*
107/389 (28%)**
6 / 7 (86%)
Minor involvement
835 / 1277 (65%)
8 /18 (28%)
99/389 (25%)
0 / 7 (0%)
1274 / 1511 (84%)
19 / 19 (100%)+
400 / 442 (90%)*
6 / 7 (86%)
Age (years)
Skeletal involvement
Whole gene del¹
n=19
PTC²
n=442
two mutations³
n=7
Major involvement
439 / 1511 (29%)
5 / 19 (26%)
183/442 (41%)
3 / 7 (43%)
Minor involvement
835 / 1511 (55%)
14 / 15 (74%)
217/442 (49%)
3 / 7 (43%)
Fisher’s test demonstrated significant differences between the total cohort and subgroups marked with a
symbol.
Abbreviations: del: deletion, PTC: premature termination codon mutation, + = p<0.05, * = p<0.01,
** = p<0.001
types and their phenotype lead to the following interesting results: 1) cysteine missense
mutations lead more often to ectopia lentis; 2) introduction of a cysteine mutation leads
to a less severe cardiovascular and skeletal phenotype than other missense mutations;
3) whole gene deletions lead to a 95% cardiovascular involvement and a 100% skeletal
involvement which is the highest of all mutation-types, but a much lower prevalence
of ectopia lentis (28%); 4) Furthermore, we found that patients with a PTC mutation
(leading to reduced amounts of normal fibrillin-1 protein) have a similar phenotype
compared to patients with a whole gene deletion (summarized in Figure 1).
Expert opinion
Since the first presentation of a patient with long slender fingers by Antoine Marfan,
MFS has evolved into a worldwide known syndrome in which the diagnosis can be
established according to clear guidelines. The introduction of mutation analysis catalysed the knowledge of different connective tissue disorders. Currently, the presence
of a pathogenic FBN1 mutation has a prominent role in the diagnosis of MFS. However,
significant uncertainties, including the large heterogeneity in phenotype and treatment
response, still remain in 2014.
77
Figure 1. An overview of different FBN1 mutation types. Missense mutations, exon skipping and minor
in frame insertions or deletions will lead to a mutant fibrillin-1 protein interfering with normal fibrillin-1.
Whole gene deletions and premature termination codons (including frameshifts and nonsense mutations)
will lead to less normal fibrillin-1 protein. The symbols identify significant differences between the mutation type and the total cohort of 1511 patients minus the patients of the mutation type.
In this review we attempt to categorize the genetic mutations in FBN1 and we give an
overview of the phenotypes associated with these different types of mutations. The
limitations of this review include the large differences in data presented by different
authors, differences in used guidelines for diagnosing MFS, and the exclusion of FBN1
mutations where no phenotype is reported. However, since we included all patients with
(partially) known phenotype, we expect that these differences are normally distributed
over all mutation-types.
Our analysis of the existing data revealed a number of interesting findings. Remarkably, patients with a PTC mutation had a similar phenotype compared to patients with
a whole gene deletion. Probably, because a PTC leads to nonsense mediated decay and
thus a reduced amount of normal fibrillin-1 protein, known as ‘haploinsufficiency’. This
78
Chapter 5: Diagnosis and genetics
phenomenon, of a reduced amount of normal fibrillin-1 leading to MFS, has already
been described by Schrijver, et al in 2002.139 Reduced prevalence of ectopia lentis and
increased prevalence of cardiovascular involvement in patients with a PTC mutation are
novel findings in our study. Absence of ectopia lentis may delay MFS diagnosis, yet these
patients are at higher risk for aortic dissection. Furthermore, the pathogenesis of patients
with a PTC mutation is different compared to patients with a missense mutation. Rapid
nonsense mediated decay of mutant transcripts leads to a loss-of-function phenotype,
and thus this phenotype resembles patients with a whole gene deletion. In contrast,
missense mutations or mutations leading to exon skipping result in the synthesis of
truncated or deformed fibrillin-1. Truncated or deformed fibrillin-1 may have a dominant
negative effect for some phenotypic features, such as ectopia lentis. On the other hand,
deformed or truncated fibrillin-1 protein may have a partially normal function, leading
to a less severe mutation-effect on skeletal features and aortic aneurysms compared to
patients with reduced amounts of normal fibrillin-1.
Our data suggest that mutation effect at protein level partly explains differences in
the development of clinical features. However, even in the group leading to truncated or
deformed fibrillin-1, differences in phenotype exist. For example, ectopia lentis was more
frequently present in patients with a cysteine missense mutation compared to patients
with a missense mutation not involving a cysteine amino acid. Thus, the structure of the
mutated fibrillin-1 protein is clearly important in the development of ectopia lentis.35
It could be speculated that the modification of fibrillin-1 also changes the fibrillin-1
function, and subsequently alters TGF-β signaling. However, more preclinical research
is needed to confirm or reject this hypothesis and to create more consensus about the
role of TGF-β in the pathogenesis of MFS. In our opinion, increased TGF-β level in MFS
is rather a readout of the disease state of the aorta than the initiator of damage/clinical
features.156
Key questions that warrant further investigation include the role of mutations in
treatment effects of beta-blockers and losartan on aortic dilation rates and aortic dissections. Currently, there are no studies investigating the treatment effects between
different mutation-types. A classification in patients with a reduced amount of fibrillin-1
and patients with expression of mutated or truncated protein may result in a different
response to treatment, and thus may reveal the first step in individualized prognosis and
treatment in MFS.
The highly variable phenotype of MFS patients may be based on mutation effect at
protein level (reduced versus truncated/deformed fibrillin-1). Further investigation at
this level is needed for individualized prognosis and treatment.
79
Declaration of interest
This work is supported by Interuniversity Cardiology Institute of the Netherlands. The
authors have no relevant affiliations or financial involvement with any organization or
entity with a financial interest in or financial conflict with the subject matter or materials
discussed in the manuscript apart from those disclosed.
Reference List
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
80
Dietz HC, Pyeritz RE. Mutations in the human gene for fibrillin-1 (FBN1) in the Marfan syndrome and related
disorders. Hum Mol Genet 1995;4 Spec No:1799-1809.
Mulder BJ. The distal aorta in the Marfan syndrome. Neth Heart J 2008;16(11):382-386
Franken R, den Hartog AW, de Waard V, et al. Circulating transforming growth factor-beta as a prognostic
biomarker in Marfan syndrome. Int J Cardiol 2013;168:2441-6.
Neptune ER, Frischmeyer PA, Arking DE, et al Dysregulation of TGF-beta activation contributes to pathogenesis
in Marfan syndrome. Nat Genet 2003;33(3):407-411.
Groenink M, Rozendaal L, Naeff MS, et al. Marfan syndrome in children and adolescents: predictive and prognostic value of aortic root growth for screening for aortic complications. Heart 1998;80(2):163-169.
Groenink M, Lohuis TA, Tijssen JG, et al. Survival and complication free survival in Marfan’s syndrome: implications of current guidelines. Heart 1999;82(4):499-504.
Rozendaal L, Groenink M, Naeff MS, et al. Marfan syndrome in children and adolescents: an adjusted nomogram
for screening aortic root dilatation. Heart 1998;79(1):69-72.
Silverman DI, Burton KJ, Gray J, et al. Life expectancy in the Marfan syndrome. Am J Cardiol 1995;75(2):157-160.
den Hartog AW, Franken R, Zwinderman AH, et al. Current and future pharmacological treatment strategies
with regard to aortic disease in Marfan syndrome. Expert Opin Pharmacother 2012;13(5):647-662.
Loeys BL, Dietz HC, Braverman AC, et al. The revised Ghent nosology for the Marfan syndrome. J Med Genet
2010;47(7):476-485.
Nollen GJ, Groenink M, van der Wall EE, et al. Current insights in diagnosis and management of the cardiovascular complications of Marfan’s syndrome. Cardiol Young 2002;12(4):320-327.
Nollen GJ, Mulder BJ. What is new in the Marfan syndrome? Int J Cardiol 2004;97 Suppl 1:103-108.
Oosterhof T, Groenink M, Hulsmans FJ, et al. Quantitative assessment of dural ectasia as a marker for Marfan
syndrome. Radiology 2001;220(2):514-518.
Marfan AB. Un cas de deformation congenitale des quarte membres plus prononcee aux extremites caracterisee par l’allongement des os avec un certain degre d’amincissement. Bull Mem Soc Med Hop Paris. 13 ed. 1896.
p. 220-226.
McKusick VA. The cardiovascular aspects of Marfan’s syndrome: a heritable disorder of connective tissue.
Circulation 1955;11(3):321-342.
Beighton P, de Paepe A, Danks D, et al. International Nosology of Heritable Disorders of Connective Tissue,
Berlin, 1986. Am J Med Genet 1988;29(3):581-594.
de Paepe A, Devereux RB, Dietz HC, et al. Revised diagnostic criteria for the Marfan syndrome. Am J Med Genet
1996;62(4):417-426.
Dietz HC, Cutting GR, Pyeritz RE, et al. Marfan syndrome caused by a recurrent de novo missense mutation in
the fibrillin gene. Nature 1991;352(6333):337-339.
Loeys BL, Chen J, Neptune ER et al. A syndrome of altered cardiovascular, craniofacial, neurocognitive and
skeletal development caused by mutations in TGFBR1 or TGFBR2. Nat Genet 2005;37(3):275-281.
Putnam EA, Zhang H, Ramirez F, et al. Fibrillin-2 (FBN2) mutations result in the Marfan-like disorder, congenital
contractural arachnodactyly. Nat Genet 1995;11(4):456-458.
Franken R, den Hartog AW, Singh M, et al. Marfan syndrome: Progress report. Progress in Pediatric Cardiology
2012;34(1):9-14.
Chapter 5: Diagnosis and genetics
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
Franken R, den Hartog AW, van de Riet L, et al. Clinical features differ substantially between Caucasian and Asian
populations of Marfan syndrome. Circ J 2013;77(11):2793-2798.
Arslan-Kirchner M, Arbustini E, Boileau C, et al. Clinical utility gene card for: Marfan syndrome type 1 and related
phenotypes [FBN1]. Eur J Hum Genet 2010;18(9).
Downing AK, Knott V, Werner JM, et al. Solution structure of a pair of calcium-binding epidermal growth factorlike domains: implications for the Marfan syndrome and other genetic disorders. Cell 1996;85(4):597-605.
Saharinen J, Keski-Oja J. Specific sequence motif of 8-Cys repeats of TGF-beta binding proteins, LTBPs, creates a
hydrophobic interaction surface for binding of small latent TGF-beta. Mol Biol Cell 2000;11(8):2691-2704.
Schrijver I, Liu W, Brenn T, et al. Cysteine substitutions in epidermal growth factor-like domains of fibrillin-1:
distinct effects on biochemical and clinical phenotypes. Am J Hum Genet 1999;65(4):1007-1020.
Booms P, Cisler J, Mathews KR, et al. Novel exon skipping mutation in the fibrillin-1 gene: two ‘hot spots’ for the
neonatal Marfan syndrome. Clin Genet 1999;55(2):110-117.
Putnam EA, Cho M, Zinn AB, et al. Delineation of the Marfan phenotype associated with mutations in exons
23-32 of the FBN1 gene. Am J Med Genet 1996;62(3):233-242.
Tiecke F, Katzke S, Booms P, et al. Classic, atypically severe and neonatal Marfan syndrome: twelve mutations
and genotype-phenotype correlations in FBN1 exons 24-40. Eur J Hum Genet 2001;9(1):13-21.
Faivre L, Collod-Beroud G, Callewaert B, et al. Clinical and mutation-type analysis from an international series of
198 probands with a pathogenic FBN1 exons 24-32 mutation. Eur J Hum Genet 2009;17(4):491-501.
Kosaki K, Takahashi D, Udaka T, et al. Molecular pathology of Shprintzen-Goldberg syndrome. Am J Med Genet
A 2006;140(1):104-108.
Le Goff C, Mahaut C, Wang LW, et al. Mutations in the TGFbeta binding-protein-like domain 5 of FBN1 are
responsible for acromicric and geleophysic dysplasias. Am J Hum Genet 2011;89(1):7-14.
Loeys BL, Gerber EE, Riegert-Johnson D, et al. Mutations in fibrillin-1 cause congenital scleroderma: stiff skin
syndrome. Sci Transl Med 2010;2(23):23ra20.
Collod-Beroud G, Le BS, Ades L, et al. Update of the UMD-FBN1 mutation database and creation of an FBN1
polymorphism database. Hum Mutat 2003;22(3):199-208.
Judge DP, Biery NJ, Keene DR, et al. Evidence for a critical contribution of haploinsufficiency in the complex
pathogenesis of Marfan syndrome. J Clin Invest 2004;114(2):172-181.
Aoyama T, Tynan K, Dietz HC, et al. Missense mutations impair intracellular processing of fibrillin and microfibril
assembly in Marfan syndrome. Hum Mol Genet 1993;2(12):2135-2140.
Ades LC, Haan EA, Colley AF, et al. Characterisation of four novel fibrillin-1 (FBN1) mutations in Marfan syndrome. J Med Genet 1996;33(8):665-671.
Aragon-Martin JA, Ahnood D, Charteris DG, et al. Role of ADAMTSL4 mutations in FBN1 mutation-negative
ectopia lentis patients. Hum Mutat 2010;31(8):E1622-E1631.
Arbustini E, Grasso M, Ansaldi S, et al. Identification of sixty-two novel and twelve known FBN1 mutations in
eighty-one unrelated probands with Marfan syndrome and other fibrillinopathies. Hum Mutat 2005;26(5):494.
Attanasio M, Lapini I, Evangelisti L, et al. FBN1 mutation screening of patients with Marfan syndrome and
related disorders: detection of 46 novel FBN1 mutations. Clin Genet 2008;74(1):39-46.
Barnett CP, Wilson GJ, Chiasson DA, et al. Central nervous system abnormalities in two cases with neonatal
Marfan syndrome with novel mutations in the fibrillin-1 gene. Am J Med Genet A 2010;152A(9):2409-2412.
Biggin A, Holman K, Brett M, et al. Detection of thirty novel FBN1 mutations in patients with Marfan syndrome
or a related fibrillinopathy. Hum Mutat 2004;23(1):99.
Booms P, Withers AP, Boxer M, et al. A novel de novo mutation in exon 14 of the fibrillin-1 gene associated with
delayed secretion of fibrillin in a patient with a mild Marfan phenotype. Hum Genet 1997;100(2):195-200.
Callier P, Aral B, Hanna N, et al. Systematic molecular and cytogenetic screening of 100 patients with Marfanoid
syndromes and intellectual disability. Clin Genet 2013;84(6):507-521.
Cecchi A, Ogawa N, Martinez HR, et al. Missense mutations in FBN1 exons 41 and 42 cause Weill-Marchesani
syndrome with thoracic aortic disease and Marfan syndrome. Am J Med Genet A 2013;161(9):2305-2310.
Chandra A, Aragon-Martin JA, Hughes K, et al. A genotype-phenotype comparison of ADAMTSL4 and FBN1 in
isolated ectopia lentis. Invest Ophthalmol Vis Sci 2012;53(8):4889-4896.
Chung BH, Lam ST, Tong TM, et al. Identification of novel FBN1 and TGFBR2 mutations in 65 probands with
Marfan syndrome or Marfan-like phenotypes. Am J Med Genet A 2009;149A(7):1452-1459.
Comeglio P, Evans AL, Brice GW, et al. Detection of six novel FBN1 mutations in British patients affected by
Marfan syndrome. Hum Mutat 2001;18(3):251.
81
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
82
Comeglio P, Evans AL, Brice GW, et al.. Gene symbol: FBN1. Disease: Marfan syndrome. Hum Genet
2003;112(1):104.
Comeglio P, Evans AL, Brice G, et al. Identification of FBN1 gene mutations in patients with ectopia lentis and
marfanoid habitus. Br J Ophthalmol 2002;86(12):1359-1362.
Comeglio P, Johnson P, Arno G, et al. The importance of mutation detection in Marfan syndrome and Marfanrelated disorders: report of 193 FBN1 mutations. Hum Mutat 2007;28(9):928.
Derbent M, Anuk D, Tarcan A, et al. Functional pulmonary atresia in a patient with neonatal Marfan syndrome
caused by a c.3602G>A mutation in exon 29 of the FBN1 gene. Clin Dysmorphol 2008;17(2):127-128.
Dietz HC, Saraiva JM, Pyeritz RE, et al. Clustering of fibrillin (FBN1) missense mutations in Marfan syndrome
patients at cysteine residues in EGF-like domains. Hum Mutat 1992;1(5):366-374.
Dietz HC, Pyeritz RE, Puffenberger EG, et al. Marfan phenotype variability in a family segregating a missense
mutation in the epidermal growth factor-like motif of the fibrillin gene. J Clin Invest 1992;89(5):1674-1680.
El-Aleem AA, Karck M, Haverich A, et al. Identification of 9 novel FBN1 mutations in German patients with
Marfan syndrome. Hum Mutat 1999;14(2):181.
Elcioglu NH, Akalin F, Elcioglu M, et al. Neonatal Marfan syndrome caused by an exon 25 mutation of the fibrillin-1 gene. Genet Couns 2004;15(2):219-225.
Ganesh A, Smith C, Chan W, et al. Immunohistochemical evaluation of conjunctival fibrillin-1 in Marfan syndrome. Arch Ophthalmol 2006;124(2):205-209.
Halliday D, Hutchinson S, Kettle S, et al. Molecular analysis of eight mutations in FBN1. Hum Genet
1999;105(6):587-597.
Halliday DJ, Hutchinson S, Lonie L, et al. Twelve novel FBN1 mutations in Marfan syndrome and Marfan related
phenotypes test the feasibility of FBN1 mutation testing in clinical practice. J Med Genet 2002;39(8):589-593.
Hayward C, Porteous ME, Brock DJ. Mutation screening of all 65 exons of the fibrillin-1 gene in 60 patients with
Marfan syndrome: report of 12 novel mutations. Hum Mutat 1997;10(4):280-289.
Hayward C, Rae AL, Porteous ME, et al. Two novel mutations and a neutral polymorphism in EGF-like domains
of the fibrillin gene (FBN1): SSCP screening of exons 15-21 in Marfan syndrome patients. Hum Mol Genet
1994;3(2):373-375.
Hewett DR, Lynch JR, Child A, et al. A new missense mutation of fibrillin in a patient with Marfan syndrome. J
Med Genet 1994;31(4):338-339.
Hilhorst-Hofstee Y, Kroft LJ, Pals G, et al. Intracranial hypertension in 2 children with marfan syndrome. J Child
Neurol 2008;23(8):954-955.
Hung CC, Lin SY, Lee CN, et al. Mutation spectrum of the fibrillin-1 (FBN1) gene in Taiwanese patients with
Marfan syndrome. Ann Hum Genet 2009;73(Pt 6):559-567.
Jin C, Yao K, Jiang J, et al. Novel FBN1 mutations associated with predominant ectopia lentis and marfanoid
habitus in Chinese patients. Mol Vis 2007;13:1280-1284.
Kainulainen K, Karttunen L, Puhakka L, et al. Mutations in the fibrillin gene responsible for dominant ectopia
lentis and neonatal Marfan syndrome. Nat Genet 1994;6(1):64-69.
Katzke S, Booms P, Tiecke F, et al. TGGE screening of the entire FBN1 coding sequence in 126 individuals with
marfan syndrome and related fibrillinopathies. Hum Mutat 2002;20(3):197-208.
Kielty CM, Rantamaki T, Child AH, et al. Cysteine-to-arginine point mutation in a ‘hybrid’ eight-cysteine domain
of FBN1: consequences for fibrillin aggregation and microfibril assembly. J Cell Sci 1995;108 ( Pt 3):1317-1323.
Kilpatrick MW, Lembessis P, Rose E, et al. A novel G to A substitution at nucleotide 1734 of the FBN1 gene
predicting a C534Y mutation responsible for marfan syndrome. Hum Hered 1999;49(3):176-177.
Klintschar M, Bilkenroth U, Arslan-Kirchner M, et al. Marfan syndrome: clinical consequences resulting from a
medicolegal autopsy of a case of sudden death due to aortic rupture. Int J Legal Med 2009;123(1):55-58.
Kochilas L, Gundogan F, Atalay M, et al. A novel mutation of the fibrillin-1 gene in a newborn with severe Marfan
syndrome. J Perinatol 2008;28(4):303-305.
Li D, Yu J, Gu F, et al. The roles of two novel FBN1 gene mutations in the genotype-phenotype correlations of
Marfan syndrome and ectopia lentis patients with marfanoid habitus. Genet Test 2008;12(2):325-330.
Liang C, Fan W, Wu S, et al. Identification of a novel FBN1 mutation in a Chinese family with isolated ectopia
lentis. Mol Vis 2011;17:3481-3485.
Loeys B, de Backer J, van Acker P, et al. Comprehensive molecular screening of the FBN1 gene favors locus
homogeneity of classical Marfan syndrome. Hum Mutat 2004;24(2):140-146.
Matsukawa R, Iida K, Nakayama M, et al. Eight novel mutations of the FBN1 gene found in Japanese patients
with Marfan syndrome. Hum Mutat 2001;17(1):71-72.
Chapter 5: Diagnosis and genetics
76.
77.
78.
79.
80.
81.
82.
83.
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
98.
99.
100.
McInnes RR, Byers PH. Biochemical genetics: examples of life after cloning. Curr Opin Genet Dev 1993;3(3):475483.
Micheal S, Khan MI, Akhtar F, et al. Identification of a novel FBN1 gene mutation in a large Pakistani family with
Marfan syndrome. Mol Vis 2012;18:1918-1926.
Montgomery RA, Geraghty MT, Bull E, et al. Multiple molecular mechanisms underlying subdiagnostic variants
of Marfan syndrome. Am J Hum Genet 1998;63(6):1703-1711.
Ng DK, Chau KW, Black C, et al. Neonatal Marfan syndrome: a case report. J Paediatr Child Health 1999;35(3):321323.
Oh MR, Kim JS, Beck NS, et al. Six novel mutations of the fibrillin-1 gene in Korean patients with Marfan syndrome. Pediatr Int 2000;42(5):488-491.
Palz M, Tiecke F, Booms P, et al. Detection of 15 novel mutations in 52 children from 40 families with the Marfan
or Loeys-Dietz syndrome and phenotype-genotype correlations. Clin Genet 2013.
Pees C, Michel-Behnke I, Hagl M, et al. Detection of 15 novel mutations in 52 children from 40 families with the
Marfan or Loeys-Dietz syndrome and phenotype-genotype correlations. Clin Genet 2013.
Pepe G, Giusti B, Attanasio M, et al. A major involvement of the cardiovascular system in patients affected by
Marfan syndrome: novel mutations in fibrillin 1 gene. J Mol Cell Cardiol 1997;29(7):1877-1884.
Pepe G, Lapini I, Evangelisti L, et al. Is ectopia lentis in some cases a mild phenotypic expression of Marfan
syndrome? Need for a long-term follow-up. Mol Vis 2007;13:2242-2247.
Milewicz DM, Grossfield J, Cao SN, et al. A mutation in FBN1 disrupts profibrillin processing and results in
isolated skeletal features of the Marfan syndrome. J Clin Invest 1995;95(5):2373-2378.
Faivre L, Collod-Beroud G, Loeys BL, et al. Effect of mutation type and location on clinical outcome in 1,013
probands with Marfan syndrome or related phenotypes and FBN1 mutations: an international study. Am J Hum
Genet 2007;81(3):454-466.
Ades LC, Sullivan K, Biggin A, et al. FBN1, TGFBR1, and the Marfan-craniosynostosis/mental retardation disorders revisited. Am J Med Genet A 2006;140(10):1047-1058.
Ades LC, Sreetharan D, Onikul E, et al. Segregation of a novel FBN1 gene mutation, G1796E, with kyphoscoliosis
and radiographic evidence of vertebral dysplasia in three generations. Am J Med Genet 2002;109(4):261-270.
Brautbar A, LeMaire SA, Franco LM, et al. FBN1 mutations in patients with descending thoracic aortic dissections. Am J Med Genet A 2010;152A(2):413-416.
Bresters D, Nikkels PG, Meijboom EJ, et al. Clinical, pathological and molecular genetic findings in a case of
neonatal Marfan syndrome. Acta Paediatr 1999;88(1):98-101.
Buoni S, Zannolli R, Macucci F, et al. The FBN1 (R2726W) mutation is not fully penetrant. Ann Hum Genet
2004;68(Pt 6):633-638.
Chao SC, Chen JS, Tsai CH, et al. Novel exon nucleotide substitution at the splice junction causes a neonatal
Marfan syndrome. Clin Genet 2010;77(5):453-463.
Collod-Beroud G, Lackmy-Port-Lys M, Jondeau G, et al. Demonstration of the recurrence of Marfan-like skeletal and cardiovascular manifestations due to germline mosaicism for an FBN1 mutation. Am J Hum Genet
1999;65(3):917-921.
Dietz HC, McIntosh I, Sakai LY, et al. Four novel FBN1 mutations: significance for mutant transcript level and
EGF-like domain calcium binding in the pathogenesis of Marfan syndrome. Genomics 1993;17(2):468-475.
Dong J, Bu J, Du W, et al. A new novel mutation in FBN1 causes autosomal dominant Marfan syndrome in a
Chinese family. Mol Vis 2012;18:81-86.
Evangelisti L, Lucarini L, Attanasio M, et al. A single heterozygous nucleotide substitution displays two different
altered mechanisms in the FBN1 gene of five Italian Marfan patients. Eur J Med Genet 2010;53(5):299-302.
Francke U, Berg MA, Tynan K, et al. A Gly1127Ser mutation in an EGF-like domain of the fibrillin-1 gene is a risk
factor for ascending aortic aneurysm and dissection. Am J Hum Genet 1995;56(6):1287-1296.
Grau U, Klein HG, Detter C, et al. A novel mutation in the neonatal region of the fibrillin (FBN)1 gene associated with a classical phenotype of Marfan syndrome (MfS). Mutations in brief no. 163. Online. Hum Mutat
1998;12(2):137.
Hayward C, Porteous ME, Brock DJ. A novel mutation in the fibrillin gene (FBN1) in familial arachnodactyly. Mol
Cell Probes 1994;8(4):325-327.
Hewett DR, Lynch JR, Smith R, et al. A novel fibrillin mutation in the Marfan syndrome which could disrupt
calcium binding of the epidermal growth factor-like module. Hum Mol Genet 1993;2(4):475-477.
83
101.
102.
103.
104.
105.
106.
107.
108.
109.
110.
111.
112.
113.
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
124.
125.
84
Hilhorst-Hofstee Y, Rijlaarsdam ME, Scholte AJ, et al. The clinical spectrum of missense mutations of the first
aspartic acid of cbEGF-like domains in fibrillin-1 including a recessive family. Hum Mutat 2010;31(12):E1915E1927.
Jacobs AM, Toudjarska I, Racine A, et al. A recurring FBN1 gene mutation in neonatal Marfan syndrome. Arch
Pediatr Adolesc Med 2002;156(11):1081-1085.
Karttunen L, Raghunath M, Lonnqvist L, et al. A compound-heterozygous Marfan patient: two defective fibrillin
alleles result in a lethal phenotype. Am J Hum Genet 1994;55(6):1083-1091.
Khau Van KP, Baux D, Pallares-Ruiz N, et al. Missense mutations of conserved glycine residues in fibrillin-1
highlight a potential subtype of cb-EGF-like domains. Hum Mutat 2010;31(1):E1021-E1042.
Liu W, Qian C, Francke U. Silent mutation induces exon skipping of fibrillin-1 gene in Marfan syndrome. Nat
Genet 1997;16(4):328-329.
Lo IF, Wong RM, Lam FW, et al. Missense mutations of the fibrillin-1 gene in two Chinese patients with severe
Marfan syndrome. Chin Med J (Engl ) 2001;114(5):473-476.
Lonnqvist L, Child A, Kainulainen K, et al. A novel mutation of the fibrillin gene causing ectopia lentis. Genomics
1994;19(3):573-576.
Lonnqvist L, Karttunen L, Rantamaki T, et al. A point mutation creating an extra N-glycosylation site in fibrillin-1
results in neonatal Marfan syndrome. Genomics 1996;36(3):468-475.
Milewicz DM, Michael K, Fisher N, et al. Fibrillin-1 (FBN1) mutations in patients with thoracic aortic aneurysms.
Circulation 1996;94(11):2708-2711.
Gillis E, Kempers M, Salemink S, et al. An FBN1 Deep Intronic Mutation in a Familial Case of Marfan Syndrome:
An Explanation for Genetically Unsolved Cases? Hum Mutat 2014;35(5):571-574.
Blyth M, Foulds N, Turner C, et al. Severe Marfan syndrome due to FBN1 exon deletions. Am J Med Genet A
2008;146A(10):1320-1324.
De Backer J, Loeys B, Leroy B, et al. Utility of molecular analyses in the exploration of extreme intrafamilial
variability in the Marfan syndrome. Clin Genet 2007;72(3):188-198.
Faivre L, Gorlin RJ, Wirtz MK, et al. In frame fibrillin-1 gene deletion in autosomal dominant Weill-Marchesani
syndrome. J Med Genet 2003;40(1):34-36.
Godfrey M, Vandemark N, Wang M, et al. Prenatal diagnosis and a donor splice site mutation in fibrillin in a
family with Marfan syndrome. Am J Hum Genet 1993;53(2):472-480.
Guo DC, Gupta P, Tran-Fadulu V, et al. An FBN1 pseudoexon mutation in a patient with Marfan syndrome:
confirmation of cryptic mutations leading to disease. J Hum Genet 2008;53(11-12):1007-1011.
Hutchinson S, Wordsworth BP, Handford PA. Marfan syndrome caused by a mutation in FBN1 that gives rise to
cryptic splicing and a 33 nucleotide insertion in the coding sequence. Hum Genet 2001;109(4):416-420.
Liu W, Qian C, Comeau K, et al. Mutant fibrillin-1 monomers lacking EGF-like domains disrupt microfibril assembly and cause severe marfan syndrome. Hum Mol Genet 1996;5(10):1581-1587.
Liu W, Schrijver I, Brenn T, et al. Multi-exon deletions of the FBN1 gene in Marfan syndrome. BMC Med Genet
2001;2:11.
McGrory J, Cole WG. Alternative splicing of exon 37 of FBN1 deletes part of an ‘eight-cysteine’ domain resulting
in the Marfan syndrome. Clin Genet 1999;55(2):118-121.
Milewicz DM, Duvic M. Severe neonatal Marfan syndrome resulting from a de novo 3-bp insertion into the
fibrillin gene on chromosome 15. Am J Hum Genet 1994;54(3):447-453.
Raghunath M, Kielty CM, Kainulainen K, et al. Analyses of truncated fibrillin caused by a 366 bp deletion in the
FBN1 gene resulting in Marfan syndrome. Biochem J 1994;302 ( Pt 3):889-896.
Rand-Hendriksen S, Tjeldhorn L, Lundby R, et al. Search for correlations between FBN1 genotype and
complete Ghent phenotype in 44 unrelated Norwegian patients with Marfan syndrome. Am J Med Genet A
2007;143A(17):1968-1977.
Rommel K, Karck M, Haverich A, et al. Identification of 29 novel and nine recurrent fibrillin-1 (FBN1) mutations
and genotype-phenotype correlations in 76 patients with Marfan syndrome. Hum Mutat 2005;26(6):529-539.
Soylen B, Singh KK, Abuzainin A, et al. Prevalence of dural ectasia in 63 gene-mutation-positive patients with
features of Marfan syndrome type 1 and Loeys-Dietz syndrome and report of 22 novel FBN1 mutations. Clin
Genet 2009;75(3):265-270.
Turner CL, Emery H, Collins AL, et al. Detection of 53 FBN1 mutations (41 novel and 12 recurrent) and genotypephenotype correlations in 113 unrelated probands referred with Marfan syndrome, or a related fibrillinopathy.
Am J Med Genet A 2009;149A(2):161-170.
Chapter 5: Diagnosis and genetics
126.
127.
128.
129.
130.
131.
132.
133.
134.
135.
136.
137.
138.
139.
140.
141.
142.
143.
144.
145.
146.
147.
148.
149.
150.
Waldmuller S, Muller M, Warnecke H, et al. Genetic testing in patients with aortic aneurysms/dissections: a
novel genotype/phenotype correlation? Eur J Cardiothorac Surg 2007;31(6):970-975.
Wang M, Price C, Han J, et al. Recurrent mis-splicing of fibrillin exon 32 in two patients with neonatal Marfan
syndrome. Hum Mol Genet 1995;4(4):607-613.
Wang WJ, Han P, Zheng J, et al. Exon 47 skipping of fibrillin-1 leads preferentially to cardiovascular defects in
patients with thoracic aortic aneurysms and dissections. J Mol Med (Berl) 2013;91(1):37-47.
Weidenbach M, Brenner R, Rantamaki T, et al. Acute mitral regurgitation due to chordal rupture in a patient with
neonatal Marfan syndrome caused by a deletion in exon 29 of the FBN1 gene. Pediatr Cardiol 1999;20(5):382385.
Faivre L, Khau Van KP, Callier P, et al. De novo 15q21.1q21.2 deletion identified through FBN1 MLPA and refined
by 244K array-CGH in a female teenager with incomplete Marfan syndrome. Eur J Med Genet 2010;53(4):208212.
Hilhorst-Hofstee Y, Hamel BC, Verheij JB, et al. The clinical spectrum of complete FBN1 allele deletions. Eur J
Hum Genet 2011;19(3):247-252.
Hutchinson S, Furger A, Halliday D, et al. Allelic variation in normal human FBN1 expression in a family with
Marfan syndrome: a potential modifier of phenotype? Hum Mol Genet 2003;12(18):2269-2276.
Matyas G, Alonso S, Patrignani A, et al. Large genomic fibrillin-1 (FBN1) gene deletions provide evidence for true
haploinsufficiency in Marfan syndrome. Hum Genet 2007;122(1):23-32.
Furtado LV, Wooderchak-Donahue W, Rope AF, et al. Characterization of large genomic deletions in the FBN1
gene using multiplex ligation-dependent probe amplification. BMC Med Genet 2011;12:119.
Schrijver I, Liu W, Odom R, et al. Premature termination mutations in FBN1: distinct effects on differential allelic
expression and on protein and clinical phenotypes. Am J Hum Genet 2002;71(2):223-237.
Behan WM, Longman C, Petty RK, et al. Muscle fibrillin deficiency in Marfan’s syndrome myopathy. J Neurol
Neurosurg Psychiatry 2003;74(5):633-638.
Chikumi H, Yamamoto T, Ohta Y, et al. Fibrillin gene (FBN1) mutations in Japanese patients with Marfan syndrome. J Hum Genet 2000;45(2):115-118.
Diaz de BA, Ruiz-Casares E, Darnaude MT, et al. Phenotypic variability in Marfan syndrome in a family with a
novel nonsense FBN1 gene mutation. Rev Esp Cardiol (Engl Ed) 2012;65(4):380-381.
Gao LG, Zhang L, Song L, et al. Identification of a novel lethal fibrillin-1 gene mutation in a Chinese Marfan family and correlation of 3’ fibrillin-1 gene mutations with phenotype. Chin Med J (Engl ) 2010;123(20):2874-2878.
Loeys B, Nuytinck L, Delvaux I, et al. Genotype and phenotype analysis of 171 patients referred for molecular
study of the fibrillin-1 gene FBN1 because of suspected Marfan syndrome. Arch Intern Med 2001;161(20):24472454.
Magyar I, Colman D, Arnold E, et al. Quantitative sequence analysis of FBN1 premature termination codons
provides evidence for incomplete NMD in leukocytes. Hum Mutat 2009;30(9):1355-1364.
Pepe G, Giusti B, Evangelisti L, et al. Fibrillin-1 (FBN1) gene frameshift mutations in Marfan patients: genotypephenotype correlation. Clin Genet 2001;59(6):444-450.
Perez AB, Pereira LV, Brunoni D, et al. Identification of 8 new mutations in Brazilian families with Marfan syndrome. Mutations in brief no. 211. Online. Hum Mutat 1999;13(1):84.
Rommel K, Karck M, Haverich A, et al. Mutation screening of the fibrillin-1 (FBN1) gene in 76 unrelated patients
with Marfan syndrome or Marfanoid features leads to the identification of 11 novel and three previously
reported mutations. Hum Mutat 2002;20(5):406-407.
Roopnariane A, Freed RJ, Price S, et al. Osteosarcoma in a Marfan patient with a novel premature termination
codon in the FBN1 gene. Connect Tissue Res 2011;52(2):157-165.
Sakai H, Visser R, Ikegawa S, et al. Comprehensive genetic analysis of relevant four genes in 49 patients with
Marfan syndrome or Marfan-related phenotypes. Am J Med Genet A 2006;140(16):1719-1725.
Sheikhzadeh S, Kade C, Keyser B, et al. Analysis of phenotype and genotype information for the diagnosis of
Marfan syndrome. Clin Genet 2012;82(3):240-247.
Singh KK, Elligsen D, Liersch R, et al. Multi-exon out of frame deletion of the FBN1 gene leading to a severe
juvenile onset cardiovascular phenotype in Marfan syndrome. J Mol Cell Cardiol 2007;42(2):352-356.
Song YH, Kim GH, Yoo HW, et al. Novel de novo nonsense mutation of FBN1 gene in a patient with Marfan
syndrome. J Genet 2012;91(2):233-235.
Uyeda T, Takahashi T, Eto S, et al. Three novel mutations of the fibrillin-1 gene and ten single nucleotide polymorphisms of the fibrillin-3 gene in Marfan syndrome patients. J Hum Genet 2004;49(8):404-407.
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151.
152.
153.
154.
155.
156.
86
Van Den Bossche MJ, Van Wallendael KL, Strazisar M, et al. Co-occurrence of Marfan syndrome and schizophrenia: what can be learned? Eur J Med Genet 2012;55(4):252-255.
Villamizar C, Regalado ES, Fadulu VT, et al. Paucity of skeletal manifestations in Hispanic families with FBN1
mutations. Eur J Med Genet 2010;53(2):80-84.
Wang B, Hu D, Xia J, et al. FBN1 mutation in Chinese patients with Marfan syndrome and its gene diagnosis
using haplotype linkage analysis. Chin Med J (Engl ) 2003;116(7):1043-1046.
Zhao F, Pan X, Zhao K, et al. Two novel mutations of fibrillin-1 gene correlate with different phenotypes of
Marfan syndrome in Chinese families. Mol Vis 2013;19:751-758.
de Vries BB, Pals G, Odink R, et al. Homozygosity for a FBN1 missense mutation: clinical and molecular evidence
for recessive Marfan syndrome. Eur J Hum Genet 2007;15(9):930-935.
Franken R, Radonic T, den Hartog AW, et al. The revised role of TGF-beta in aortic aneurysms in Marfan syndrome. Neth Heart J 2015;23(2):116-21.