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Short reports
64
patient was trisomic for the region 16q21-qter with
a karyotype of 46,XX,-9,+der(9),t(9;16)(p24;q21)mat
(figure). The father's blood chromosomes were normal.
The child was born at term after an uncomplicated
pregnancy to unrelated Polish parents (mother 32, father
35). Birth weight was 2325 g, length 46 cm, and head
circumference 32-5 cm. The newborn period was complicated by respiratory distress, a right pneumothorax,
persistent fetal circulation secondary to meconium aspiration, and hypoglycaemia. The mother had a history of two
previous miscarriages, each at three to foij months'
gestation. An older brother was reported to be in good
health and the family history was negative for mental
retardation and congenital malformations.
Abnormal features noted at birth and in subsequent
examinations were a long face, coarse hair, prominent
forehead with bossing, prominent nasal bridge with beak
shaped nose, bilateral epicanthic folds, short palpebral
fissures, strabismus, thin upper lip, micrognathia, high
narrow palate with ridges, low set and posteriorly,rotated
ears, short fingers with deep, abnormal palmar creases,
clinodactyly of the fifth fingers, widely spaced nipples,
hypotonia, and psychomotor retardation. No other
anomalies of organ systems were detected. Echocardiograms, skull x rays, head and abdominal ultrasound
studies, TORCH titres, and CMV culture were normal.
Partial trisomy 16q is a rare disorder with significant
dysmorphism, psychomotor retardation, and reduced
survival in liveborn infants.' 2 Garau et all postulated that
trisomy 16q is mainly responsible for prenatal lethality of
full trisomy 16. While partial trisomy 16q arises as the
result of balanced parental translocations, the involvement
of chromosomes in the translocations is not random.3 In a
review of 12 known cases of partial trisomy 16q,2 and in
our own patient, translocations involved chromosomes 15,
22, 18, 21, 9, and 11. The trisomic segment in six patients,
including ours, was 16q21--qter. Of the remaining seven
e0
I
L
i.
9
16
FIGURE G banded partial karyotype showing
chromosomes 9 and 16 from (a) the patient's mother and
(b) the patient.
cases, four were trisomic for the region 16q1 1 or q13--qter,
one was trisomic for the complete long arm of chromosome
16, and two were undefined. Patients with a longer
trisomic segment tended to have shorter survival and a
higher incidence of congenital heart disease (80%) than
did those who were trisomic for the distal half of the long
arm, heart defects being present in 17% of the latter cases.
Our case has many of the clinical features that appear to
make partial trisomy 16q a recognised phenotype.
The patient of Buckton and Barr' was similar to ours in
that the translocation involved chromosome 9 with a
possible monosomic segment of 9p24--pter. However, in
contrast to our patient, theirs had a two-thirds distal
trisomic segment, a more severe phenotype, including
flexion deformities and heart and cerebral defects, and
died at eight days of age. The length of the trisomic
segment appears to influence clinical severity and longevity
among patients with partial trisomy 16q.
MiRA L LEsSICK, JEANNETFE ISRAEL,
PAUL W K WONG, AND KATARINA SZEGO
Section of Genetics, Rush-Presbyterian-St Luke's
Medical Center, Rush University, Chicago,
Illinois 60612, USA.
References
l Garau A, Crisponi G, Peretti D, Vanni R, Zuffardi 0. Trisomy
16q21- qter. Hum Genet 1980;53:165-7.
2 Calva P, Frias S, Carnevale A, Reyes P. Partial trisomy 16q
resulting from maternal translocation llp/16q. Ann Genet
(Paris) 1984;;7:122-5.
3 Buckton
DGD. Partial trisomy for long arm of
K5,16.Barr
chromosom9
J Med Genet 1981;18:483.
Correspond4nce and requests for reprints to Dr M L
Lessick, Settion of Genetics, Rush-Presbyterian-St Luke's
Medical Center, 1750 W Harrison Street, Chicago, Illinois
60612, USA.
Duplication 6p and deletion 9p
Duplications of 6p are rarely seen. We report a newborn
male with a duplication of 6p and a concomitant deletion of
9p.
The patient was born at term after a pregnancy
complicated by intrauterine growth retardation noted ultrasonographically. Birth weight was 2126 g. There was
no known exposure to cigarette smoking, alcohol, or
medication. A detailed family history showed two miscarriages and a stillborn male in the maternal lineage and
one miscarriage in the paternal lineage. The parents were
non-consanguineous.
At birth the patient was noted to have valvular
pulmonary stenosis, a ventriculoseptal defect, and a patent
ductus arteriosus; bilateral talipes calcaneovalgus with
vertical tali; bilateral radial hypoplasia, camptodactyly,
Received for publication 16 February 1988.
Revised version accepted for publication 28 March 1988.
~i
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Short reports
A.
*,,i
*w
65
4#
i:
*
ft
.0
*
4
o
#* s
'A
:.4.
4'
o
It.
4
4%
A
3s'
I
I
g
*b
I1N
FIG 1 Frontal and lateral views of the proband.
and abnormal palmar creases; ambiguous genitalia with
microphallus, a left hydrocele and left inguinal hernia; and
a small,
proximally placed anus.
At the age of four and a half months, in addition to the
above congenital malformations, the patient had marked
postnatal growth retardation, microcephaly, and striking
craniofacial dysmorphism (fig 1) with prominent frontal
bossing and trigonocephaly, upswept frontal hair pattern
with marked hirsutism of the forehead, low set, posteriorly
rotated ears with a thickened helix and markedly prominent
antihelix, a 'beaky' nose, a thick, wide philtrum with a
small notch in the vermilion border of the lip lateral to the
right pillar of the philtrum, a high palate with thick
palatine ridges, micrognathia, and a short neck.
..
'4 ~
**
6
-
4.
6
der 9
9
FIG 2 Composite partial karyotype: normal chromosome
6, der(9), t(6;9) (pl l;p24), and normal chromosome 9.
High resolution chromosome analysis was performed on
peripheral blood. One hundred GTG banded cells showed
a 46,XY,-9,+der(9),t(6;9)(pll;p24) chromosome complement. This karotype indicates a duplication of the
majority of the short arm of chromosome 6 (6pll-*pter)
and a deletion of a distal region of the short arm of
chromosome 9 (9p24-*pter) (fig 2). Subsequent parental
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66
Short reports
3 Ferrando P, San Roman C, Rodriguez de Cordoba
TABLE Comparison of dysmorphic characteristics.
Clincal features
Dup(6p)
Del(9p)
Present patient
Mental retardation
Growth retardation
Microcephaly
+
+
+
+
+
+
4
Trigonocephaly
Hydrocephalus
High forehead
Prominent nasal bridge
Short nose
Flat nasal bridge
Long philtrum
Low set ears
Posteriorly rotated ears
Short, broad neck
Widely spaced nipples
Congenital heart defects
Renal abnormalities
Ambiguous genitalia
Hypospadias
Cryptorchidism
+
+
+
Hernias
Radial abnormalities
-_
+
_
_
-
+
+
+
+
5
_
+
+
-
++
6
7
++
+
-
+
+
+
NR
+
+
+
+
-
_
+
+
+
+
_
+
+
8
Ann Genet (Paris) 1976;19:11-6.
Correspondence and requests for reprints to Dr J Allanson,
The Genetics Center of Southwest Biomedical Research
Institute, 6401 East Thomas Road, Scottsdale, Arizona
85251, USA.
-
+
_
_
Club feet
+
+
+
Scoliosis
-
+
NR
S, et al.
Partial trisomy 6p: 46,XX,-10,der(10),t(6;10)(p22;q26)pat and
HLA localisation. J Med Genet 1981;18:231-4.
Pagano L, Fioretti G, Vertrella M, et al. Hereditary 3;6
translocation: three cases of multiple malformations with partial
trisomy 6p21-pter. Ann Genet (Paris) 1980;23:173-5.
Rosi G, Venti G, Migliorini Bruschelli G, et al. Trisomy 6p226pter due to familial t(6;13)(p22;q34 or 33) translocation. Hum
Genet 1979;51:67-72.
Therkelsen AJ, Klinge T, Henningsen K, et al. A family with a
presumptive C/F translocation in five generations. Ann Genet
(Paris) 1971;14:13-21.
Schinzel A. Catalogue of unbalanced chromosome aberrations in
man. Berlin: de Gruyter, 1984: 259-61, 350-2.
Alfi OS, Donnell GN, Allderdice PW, et al: The 9p- syndrome.
The megacystis-microcolonintestinal hypoperistalsis
chromosome studies were normal, indicating a de novo
autosomal
syndrome: a fatal
rearrangement in the patient.
dit
Duplications of 6p aIre exceedingly rare and are generally r
i
recessive cond
e aon
familin
c^odnntinru LO lUMliHI
aI tranclJu-ntinn
ha
u
1a ('.r
%UL nntipnt
"tLIV1L
LransldlUClLu.
suclnury
a
tn a
6
llilb a
duplication involving a greater portion of 6p than those
previously reported. He has the classical facial dysmorphism
associated with 6p duplications, including flat facies with a
high forehead, broad, prominent nasal bridge, short nose,
small mouth with thin lips, and low set ears.
Cases with a deletion of the short arm of chromosome 9
generally present with a clinically defined phenotype.78
These distinctive features, which our patient also shows,
include trigonocephaly, flat nasal bridge, long philtrum,
low set, posteriorly rotated ears, micrognathia, and a short
neck.
The table outlines the features seen with 6p duplications
and 9p deletions and the features of our patient are
compared to these phenotypes. As mentioned above, he
has characteristics of both conditions. He clearly has
additional anomalies which may be secondary to the size of
his 6p duplication.
A detailed review of published reports suggests that our
case is the first reported de novo rearrangement resulting
in duplication of 6p and deletion of 9p. It also involves the
largest region of 6p reported in a liveborn infant to date.
CHRISTIAN LYTLE, JON WADE, ANNA FARRIER,
FRED FLOHRSCHUTZ III, BARBARA HECHT,
AND JUDrH ALLANSON
The Genetics Center of Southwest Biomedical
Research Institute,
Scottsdale, Arizona 85251, USA.
References
2
Bernheim A, Berger R, Vaugier G. Partial trisomy 6p. Hum
Genet 1979;48:13-6.
Chiyo H, Kuroki Y, Matsui I, et al. A 6p trisomy detected in a
family with a "giant satellite". Hum Genet 1975;30:63-7.
SUMMARY We report the cases of two sibs with the
megacystis-microcolon-intestinal hypoperistalsis syndrome. The parents are first cousins. These cases further
support the view that this syndrome is inherited in an
autosomal recessive fashion.
Case reports
Cases 1 and 2 are the second and fourth pregnancies of a
consanguineous couple of Indian origin. Both parents were
normal and the family history was unremarkable. The first
pregnancy resulted in a 12 week spontaneous abortion and
the third in the birth of a normal male infant at term.
CASE
1
Prenatal. Uneventful until 31 weeks' gestational age when
the mother was admitted in preterm labour. Initially
controlled with ritodrine, but labour became established.
Birth. Lower segment caesarian section was performed
because of the preterm breech presentation. There was
difficulty in delivery and resuscitation because the fetal
abdomen was distended.
Clinical examination. A liveborn female infant, weight
2050 g, was delivered and 475 ml of clear fluid was drained
from a suprapubic puncture. On examination the child
appeared to have deficient anterior abdominal wall
Received for publication 8 December 1987.
Revised version accepted for publication 13 April 1988.
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Duplication 6p and deletion 9p.
C Lytle, J Wade, A Farrier, F Flohrschutz, 3rd, B
Hecht and J Allanson
J Med Genet 1989 26: 64-66
doi: 10.1136/jmg.26.1.64
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