A New Kindred With Pseudohypoaldosteronism Type II and
a Novel Mutation (564D>H) in the Acidic Motif of the
WNK4 Gene
Amir P. Golbang, Meena Murthy, Abbas Hamad, Che-Hsiung Liu, Georgina Cope,
William Van’t Hoff, Alan Cuthbert, Kevin M. O’Shaughnessy
Downloaded from http://hyper.ahajournals.org/ by guest on June 18, 2017
Abstract—We identified a new kindred with the familial syndrome of hypertension and hyperkalemia (pseudohypoaldosteronism type II or Gordon’s syndrome) containing an affected father and son. Mutation analysis confirmed a single
heterozygous G to C substitution within exon 7 (1690G⬎C) that causes a missense mutation within the acidic motif of
WNK4 (564D⬎H). We confirmed the function of this novel mutation by coexpressing it in Xenopus oocytes with either
the NaCl cotransporter (NCCT) or the inwardly rectifying K-channel (ROMK). Wild-type WNK4 inhibits 22Na⫹ flux in
Xenopus oocytes expressing NCCT by ⬇90% (P⬍0.001), whereas the 564D⬎H mutant had no significantly inhibitory
effect on flux through NCCT. In oocytes expressing ROMK, wild-type WNK4 produced ⬎50% inhibition of
steady-state current through ROMK at a ⫹20-mV holding potential (P⬍0.001). The 564D⬎H mutant produced further
inhibition with steady-state currents to some 60% to 70% of those seen with the wild-type WNK4. Using
fluorescent-tagged NCCT (enhanced cyan fluorescent protein–NCCT) and ROMK (enhanced green fluorescent
protein–ROMK) to quantify the expression of the proteins in the oocyte membrane, it appears that the functional effects
of the 564D⬎H mutation can be explained by alteration in the surface expression of NCCT and ROMK. Compared with
wild-type WNK4, WNK4 564D⬎H causes increased cell surface expression of NCCT but reduced expression of
ROMK. This work confirms that the novel missense mutation in WNK4, 564D⬎H, is functionally active and highlights
further how switching charge on a single residue in the acid motif of WNK4 affects its interaction with the
thiazide-sensitive target NCCT and the potassium channel ROMK. (Hypertension. 2005;46:1-6.)
Key Words: kinase 䡲 mutation
T
he familial syndrome of hypertension and hyperkalemia,
also known as pseudohypoaldosteronism type II (PHA2) or
Gordon’s syndrome, was first described some 40 years ago.1 At
least 3 different genetic loci have been identified for this
monogenic syndrome with a further locus likely2– 6 (OMIM
145260, ⫹601844, and ⫹605232). Recent collaborative work
from the Lifton and Jeunemaitre laboratories has identified 2 of
these loci as members of the novel family of serine–threonine
kinases WNK4 and WNK1.7 The WNK acronym referring to
their lack of a crucial lysine residue that normally coordinates
ATP in other kinase proteins (WNK; With No K⫽lysine). How
these kinases might cause the phenotype of Gordon’s syndrome
was not immediately apparent until renal electrolyte data were
reported suggesting the thiazide-sensitive NaCl cotransporter
(NCCT) was activated.8 Coexpression studies in the Xenopus
oocytes have subsequently confirmed that WNKs appear to
downregulate NCCT function, and that this property is lost in
WNK4 protein carrying mutations identified in Gordon’s pedi-
grees.9,10 Further work has suggested that the surface expression
of other proteins may be affected, including the inwardly
rectifying K-channel (ROMK) itself, which is responsible for K
secretion in the distal nephron.11,12
Despite the interest in WNK kinases, Gordon’s syndrome is extremely rare and only 4 WNK4 mutations have
been reported to date in published pedigrees.13 We describe here a new pedigree with Gordon’s syndrome
caused by a novel missense mutation in exon 7 on the
WNK4 gene (564D⬎H). The mutation lies within a motif
of predominantly negatively charged amino acids that is
conserved across all of the WNK genes (EPEEPEADQH),
although the function of this “acidic” motif is unknown.
By expressing this mutant in Xenopus oocytes, we have
been able to confirm that the 564D⬎H mutation produces
the same functional changes in the WNK4 protein as
reported with other mutations that alter amino acid charge
within the acidic motif of WNK4.9,10,12
Received March 21, 2005; first decision April 13, 2005; revision accepted May 1, 2005.
From the Clinical Pharmacology Unit, and the Department of Medicine (M.M., A.C.), University of Cambridge, United Kingdom; and NephroUrology
Unit, Great Ormond Street Hospital, London, United Kingdom (W.V.H.).
Amir Golbang and Meena Murthy contributed equally to the work.
Correspondence to Dr K.M. O’Shaughnessy Clinical Pharmacology Unit Level 6, ACCI Box 110, Addenbrooke’s Hospital Cambridge, CB2 2QQ, UK.
E-mail [email protected]
© 2005 American Heart Association, Inc.
Hypertension is available at http://www.hypertensionaha.org
DOI: 10.1161/01.HYP.0000174326.96918.d6
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Hypertension
August 2005
Methods
Mutation Analysis
Genomic DNA was isolated from peripheral blood cells using a
standard commercial method (Genomic Wizard kit; Promega). PvuII
digests of this gDNA was Southern blotted and hybridized to
[32P]-labeled probes as described by Wilson et al.7 The 18 coding
exons of WNK4 were individually polymerase chain reaction (PCR)
amplified using Taq polymerase (Promega; primer sequences available on request). The PCR products were then gel purified before
sequencing in both directions using an ABI 377 and Big Dye
fluorescent chemistry (Applied Biosystems).
Cloning and cRNA Synthesis
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Full-length cDNA for human ROMK2 was identified in an IMAGE
clone (4611308) and then subcloned into pEGFP-C1 to produce an
enhanced green fluorescent protein (EGFP) fusion with the N
terminal of ROMK2. Full-length sequences for NCCT and WNK4
were PCR amplified from mouse kidney cDNA and cloned into
pcDNA3. The wild-type sequence of WNK4 was mutated to produce
564D⬎H and 562Q⬎E mutants using site-directed mutagenesis. The
sequence for NCCT was also cloned into pECFP-C1 to produce a
cyan fluorescent protein fusion with its N terminal. All clones were
verified by sequencing before being used to run off cRNA. Copy
RNA was transcribed in vitro from linearized plasmids using either
the T7 or SP6 mMESSAGE mMACHINE kit (Ambion) and quantitated by ultraviolet absorption spectroscopy.
The ROMK current was defined as the difference between these 2
curves. The clamp potential of the TEVC amplifier (OC-725C
amplifier; Warner Instruments) was controlled using the program
Pulse and Pulsefit (HEKA Electronic) in conjunction with an ITC-16
interface (Computer Interface Instrutech Corporation). Data were
filtered at 1 kHz.
Membrane surface expression measurements were performed
either 3 days (for EGFP-ROMK) or 5 days (for ECFP–NCCT) after
injection. Membrane surface expression of ECFP-NCCT and EGFPROMK was determined by laser-scanning confocal microscopy with
a Leica DMRXA confocal microscope. All images were captured
using an equatorial section through each oocyte using a ⫻10
objective lens with brightness and contrast settings kept constant for
all oocytes in each injection series. The fluorescent signal in the
membrane was quantified using Leica confocal software (version
2.61 of LCS Lite), with sampling made at 16 equispaced points on
the circumference and averaged to give mean total fluorescence
intensity in arbitrary fluorescence units.
Data Analysis
For all oocyte experiments, 10 to 15 oocytes were injected for each
cRNA used. Differences between groups were compared by 1-way
ANOVA with post hoc comparison by t testing. Figures show
representative experiments that were replicated using ⱖ4 different
batches of oocytes from different donor animals. The SPSS statistical
package (software version 11) was used throughout with significance
defined as P⬍0.05.
Expression in Xenopus Oocytes
Xenopus laevis eggs were harvested and defolliculated as detailed
previously.13 cRNA (10 ng of either NCCT or ROMK) was injected
in a total volume of 100 nL per oocyte, and for coinjections
involving WNK4 or one of the mutants, an additional 10 ng of
WNK4 cRNA was added to the injectate. Water-injected oocytes
were used as controls throughout. Oocytes were then incubated in
ND96 containing 2 mmol/L sodium pyruvate and 0.1 mg/mL
gentamicin at 18°C for 2 to 3 days before use as detailed
previously.13
For 22Na flux studies, oocytes were placed for 24 hours in Cl⫺-free
ND96 solution containing 96 mmol/L sodium isethionate, 2 mmol/L
potassium gluconate, 1.8 mmol/L calcium gluconate, 1 mmol/L
magnesium gluconate, 5 mmol/L HEPES, 2.5 mmol/L sodium
pyruvate, and 5 mg/dL gentamicin. Thirty minutes before addition of
uptake medium, oocytes were added to ND96 (Cl⫺ and K⫹ free) with
inhibitors (1 mmol/L ouabain, 100 ␮mol/L amiloride, and
100 ␮mol/L bumetanide), according to the protocol of Gamba et al.14
Oocytes were then transferred to isotonic uptake medium
(58 mmol/L NaCl, 38 mmol/L N-methyl-D-glucamine, 2 mmol/L
KCl, 1.8 mmol/L CaCl2, 1 mmol/L MgCl2, and 5 mmol/L HEPES,
with inhibitors, pH 7.4) containing 22Na⫹ at a final concentration of
2.5 ␮Ci/mL and incubated in a gently shaking incubator at 30°C for
1 hour. Oocytes were then washed 5⫻ with 6 mL ice-cold aliquots
of isotonic uptake medium and the oocytes counted individually in a
gamma counter (Perkin–Elmer Cobra 5003). Thiazide sensitivity
was shown by abolition of 22Na⫹ uptake with 100 ␮mol/L hydrochlorothiazide (data not shown).
Two-electrode voltage clamp (TEVC) recording used microelectrodes filled with 3 mol/L KCl (1 to 3 mol/L⍀) for voltage sensing
and current passing. External voltage and current electrodes consisted of fine, chloride-coated silver wires. Oocytes were held in a
small chamber and perfused continuously with ND96 (2 mL/min) at
room temperature (18°C to 20°C). After impaling, oocytes were held
at a holding potential of ⫺60 mV. Current voltage (I-V) plots were
obtained from voltage step protocols ranging from ⫺140 mV to ⫹40
mV in 20-mV increments. Oocytes were held at each voltage step for
500 ms, with 100-ms intervals between the voltage steps. For the I-V
plots, the steady-state current at each voltage step was used. Initially,
oocytes were clamped at ⫺60 mV in ND96, and when stable, the
perfusing solution was switched to high-K⫹ ND96 and I-V plots
obtained. The high-K⫹ ND96 was changed to high K⫹ ND96
containing 2 mmol/L BaCl2 and a second set of I-V plots obtained.
Results
Clinical Details
A 22-year-old male presented with migraine and was found to
have hypertension and hyperkalemia. No family history was
available, in particular for his grandparents. He was treated
initially with a low potassium diet and 10 mg of propranolol
per day with some effect. Investigations at 26 years (then off
treatment) showed a blood pressure of 150/95, plasma sodium
137 mmol/L, potassium 8.2 mmol/L, bicarbonate
16.2 mmol/L, chloride 119 mmol/L, urea 4.1 mmol/L, and
creatinine 106 ␮mol/L. A Synacthen test was normal (cortisol
rising from baseline 193 to 603 nmol/L at 1 hour), recumbent
renin ⬍0.2 pmol/mL per hour, and serial ambulant aldosterone levels were 364, 420, and 676 pmol/L. A diagnosis of
PHA2 (Gordon’s syndrome) was made, and he responded to
0.5 mg of cyclopenthiazide per day, achieving a normal blood
pressure and plasma potassium a week later. He remains
normotensive with normal plasma potassium at age 38 years.
The patient had 2 children who were screened for the
condition after the diagnosis had been made. His daughter
had normal blood pressure and plasma potassium on several
occasions (between 2 and 12 years of age). The 4-year-old
boy had been born prematurely at 36 weeks gestation but had
had no neonatal illnesses and was symptomatic. His weight
was on the second centile and height 25th centile for age, and
his blood pressure was 100/60. Investigations showed
142 mmol/L plasma sodium, 6.7 mmol/L potassium,
13 mmol/L bicarbonate, 110 mmol/L chloride, and
48 mmol/L creatinine. Plasma renin was 0.6 pmol/mL per
hour (normal 2.8 to 4.5) and aldosterone ⬍69 pmol/L (normal
330 to 830). These results were considered consistent with
PHA2, and he was treated with hydrochlorothiazide with a
prompt (within a week) normalization in his plasma potassium. At 14 years of age, he remains well on 1.25 mg of
Golbang et al
Novel WNK4 Mutation Causing PHA2
3
Figure 1. The kindred shows the affected
father and son as filled squares and the
unaffected mother and daughter as open
circles. Sequencing chromatograms indicate the heterozygous G to C base
change in affected subjects, which
causes a missense mutation (564D⬎H) in
the downstream half of the acidic motif
of WNK4.
bendroflumethiazide per day, normotensive, with normal
plasma potassium (4.7 mol/L).
Downloaded from http://hyper.ahajournals.org/ by guest on June 18, 2017
Genetic Screening
Southern blots of PvuII digests of genomic DNA from the 4
pedigree members showed no hybridization differences to
normotensive control samples.7 To screen the WNK4 gene,
individual exons were PCR amplified and the products
directly sequenced. This revealed a single missense mutation
in exon 7 of WNK4 in the affected father and son, which
converts an aspartic acid residue within the highly conserved
acidic motif of WNK4 to a histidine (564D⬎H; Figure 1).
The father and son were heterozygous for this mutation in
keeping with the autosomal dominant inheritance seen in
other pedigrees with Gordon’s syndrome. There were no
other mutations detected, and all of the unaffected mother’s
and daughter’s WNK4 exons showed wild-type sequence.
Functional Studies
To establish that this WNK4 mutation is the disease-causing
mutation in our pedigree, we investigated its function first by
coexpressing it with NCCT to assess its effect on this NCCT.
Xenopus oocytes injected with NCCT cRNA demonstrated a
3- to 5-fold increase in 22Na⫹ uptake over water-injected
controls (Figure 2). The coinjection of cRNA for wild-type
WNK4 with NCCT caused almost complete inhibition of this
flux. However, coinjection of cRNA for the mutant 564D⬎H
WNK4 produced no significant inhibition of the 22Na⫹ flux,
which was not significantly different from NCCT alone. This
behavior of the mutant 564D⬎H protein is identical to that
seen with previously reported WNK4 mutation, 562Q⬎E
(Figure 2).9
We next assessed the effect of the 564D⬎H mutation on
the interaction of WNK4 with the ROMK K-channel in
voltage-clamped oocytes injected with cRNA for the
ROMK2 isoform of ROMK. Expression of ROMK alone
produced the expected inwardly rectifying I-V plot, which
was substantially inhibited by coinjection of wild-type
WNK4 cRNA (Figure 3A). Coinjection of cRNA for the
564D⬎H WNK4 mutation produced significant reduction in
the steady-state current through ROMK, which was also seen
after coinjection of ROMK with the 562Q⬎E WNK4 mutation (Figure 3B).
The effects of previously reported WNK4 mutations with
NCCT and ROMK have been explained by a reduction in
their surface expression. Therefore, we coexpressed the
564D⬎H WNK4 mutation in oocytes expressing either
ROMK as a green fusion protein (EGFP-ROMK) or NCCT as
a blue fusion protein (ECFP-NCCT). These experiments
confirm that surface expression in Xenopus changes in
parallel with the function of the native proteins when they are
coexpressed with wild-type WNK4 or the 564D⬎H mutation
(Figures 4 and 5).
Discussion
Figure 2. The 22Na flux (mean⫾SEM) for oocytes injected with
cRNA as indicated. Oocytes injected with H2O or NCCT plus
wild-type (WT) WNK4 were significantly different from NCCT
alone (*P⬍0.001). The mutations (564D⬎H and 562Q⬎E) were
not significantly different from NCCT alone.
We report here a novel missense mutation in WNK4
(564D⬎H), which shows the same functional properties as
other nonconservative mutations reported within the acidic
motif. The striking feature of these missense mutations is
their divergent behavior versus NCCT and ROMK. Although
wild-type WNK4 reduces surface expression of both these
proteins, the mutations behave as loss-of-function mutations
versus NCCT but gain-of-function mutations versus ROMK.
Coexpression of the 564D⬎H mutant actually had no significant effect on ECFP-NCCT fluorescence, whereas it produced significantly greater suppression of EGFP-ROMK than
wild-type WNK4 (Figure 5). This divergence has led to
4
Hypertension
August 2005
Figure 3. A, Typical I-V plots for oocytes
expressing ROMK channels either alone
or coexpressed with wild-type (WT)
WNK4. B, In a different batch of oocytes
the plateau current (␮A) through ROMK
at a holding potential of ⫹20 mV in the
presence of WT WNK4 or the 2 mutations (564D⬎H and 562Q⬎E). Data
points are mean⫾SEM. Asterisk indicates significant difference from WT;
P⬍0.01.
Downloaded from http://hyper.ahajournals.org/ by guest on June 18, 2017
speculation that WNK4 acts as gatekeeper molecule to
balance salt homeostasis via NCCT and K secretion through
ROMK.12
The hyperkalemia seen in Gordon’s syndrome distinguishes it from other monogenic hypertension syndromes,
which characteristically cause hypokalemia. The degree of
hyperkalemia can be dramatic, with levels of ⬎8 mmol/L
reported in untreated individuals.15,16 Its origin was puzzling,
although increased NCCT activity in the distal convoluted
tubule would be expected to reduce NaCl entering the
collecting duct, hence reducing electrogenic Na⫹ uptake and
subsequent K⫹ secretion through ROMK. Based on the 6- to
7-fold shift in sensitivity to thiazides reported in subjects with
Gordon’s, in vivo activation of NCCT appears to be substantial.8 The studies in Xenopus also suggest a similar difference
in terms of NCCT expression between wild-type WNK4 and
mutants carrying typical disease mutations such as 564D⬎H
(Figures 4 and 5). However, reduction in Na⫹ uptake through
epithelial Na⫹ channel (ENaC) may provide insufficient K⫹
conservation alone to cause hyperkalemia. Even in the
presence of pharmacological inhibition of ENaC with amiloride, hyperkalemia is unusual in subjects who have normal
renal function. This has prompted the search for a direct
effect of WNK4 on ROMK function,12 and as we have shown
Figure 4. Representative confocal images of oocytes expressing
EGFP-ROMK (green) or ECFP-NCCT (blue) alone or coexpressed with wild-type (WT) or mutant WNK4 (564D⬎H).
here, WNK4 very substantially inhibits ROMK expression
with further suppression by 564D⬎H and another acidic
motif mutation 562Q⬎E.
Loss-of-function mutations in ROMK itself are associated
with hyperkalemia, although it is only seen transiently in the
antenatal period (OMIM 241200 or type 2 Bartter’s).17,18
Subjects also show salt wasting and hypotension outside the
antenatal period because reduced secretion of K⫹ through
ROMK in the thick ascending limb (TAL) directly limits
operation of the Na,K,2Cl-cotransporter. WNK4 mutations
that cause profound suppression of ROMK expression might
be expected to cause a similar effect on loop function. There
may be several reasons why this does not occur in subjects
with Gordon’s syndrome. First, subjects with Gordon’s syn-
Figure 5. Quantitative surface membrane fluorescence for
oocytes expressing either ECFP-NCCT (A) or EGFP-ROMK (B)
and injected with wild-type (WT) WNK4 or one of the mutants
(564D⬎H or 562Q⬎E). Data points are mean⫾SEM (SEM for
H2O are within the solid bar) and *H2O and WT are significantly
different from NCCT or ROMK (P⬍0.001) and **564D⬎H and
562Q⬎E significantly different from ROMK⫹WT (P⬍0.01).
Golbang et al
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drome may be able to cope with the large amount of NaCl
exiting the loop if ROMK expression were reduced here
because of NCCT activation in the adjacent segment of the
nephron. Alternatively, the selective expression of WNK4
within the distal convoluted tubule (DCT) and not TAL could
explain why ROMK expression is preserved in the TAL.
Another explanation may be that WNK4 affects ROMK
expression in an isoform-specific manner. In the rat, ROMK
isoforms1–3 are differentially expressed along the nephron,
with ROMK1 the predominant isoform in the collecting
duct.19 It is also notable that hyperkalemia in type 2 Bartter’s
usually occurs with subjects with gene deletions removing
isoforms 2 and 3.17 Nevertheless, our studies and those
reported previously by Kahle et al used the ROMK2 isoform,12 which, in the rat, is expressed in the TAL and
collecting duct.19
The reduced surface expression caused by WNK4 could
reflect either reduced insertion of NCCT/ROMK into the
membrane or their increased removal. For ROMK, evidence
using a dynamin mutant protein suggests that WNK4 may
accelerate its removal by a clathrin-mediated degradation
pathway.12 How WNK4 affects the components of NCCT
trafficking has not been investigated and clathrin recognition
motifs are not present in NCCT. The reduced expression of
NCCT is also distinct from ROMK in requiring intact kinase
activity. This is intriguing because evidence that phosphorylation either affects or is necessary for NCCT trafficking is
sparse,20 and of course, the phosphorylation target for WNK4
may not be NCCT itself. The presence of disease-causing
WNK4 mutations in the acidic motif or C-terminal coil– coil
domain probably does not affect kinase activity and further
suggests that protein–protein interactions are a necessary part
of the NCCT-WNK4 interaction.7
A genome-wide search based on the Framingham cohort
has reported a hypertension locus on chromosome 17, which
actually sits directly over the WNK4 gene.21 These and other
data have led to the suggestion that WNK4 dysfunction might
be important in a general hypertensive population. Published
pedigrees with Gordon’s syndrome are very infrequent in the
literature, as is the case for other monogenic hypertension
syndromes such as Liddle’s and apparent mineralocorticoid
excess. However, WNK4 mutations causing milder phenotypes may exist. Mutation scanning of ⬇1000 Japanese
patients with hypertension or renal failure has identified 3
further missense mutations in WNK4.22 No data were presented on their functional activity, and the exon 7 mutation
they reported (556P⬎T) is outside of the acidic motif; in fact,
none of the substitutions occur in residues that are species
conserved. There are no reports of common functional
polymorphisms within WNK4 in non-Japanese populations.
Hence, there is no evidence at present to suggest that WNK4
contains common risk alleles for essential hypertension.
The discovery of a crucial regulatory role for WNKs in the
distal nephron has come about through the molecular cloning
of just 2 of the known loci for Gordon’s syndrome. Our new
pedigree confirms that the disease mutations in WNK4
cluster in the acidic motif. Why this motif is important is
presently unknown, but charge changes in this run of 10
amino acids profoundly disturb the function of WNK4. More
Novel WNK4 Mutation Causing PHA2
5
work is needed to define the structure of the WNK4 protein
as well as its interacting partners. Cloning the remaining loci
for Gordon’s syndrome may provide further clues as to this
regulatory process or even identify other interacting proteins.
Perspectives
Establishing the molecular basis for rare monogenic syndromes such as Gordon’s syndrome can shed important light
on salt homeostasis in the kidney. Work in the last couple of
years has identified mutations in the genes encoding 2 novel
serine/threonine kinases, WNK1 and WNK4, as the cause of
the Gordon’s phenotype of hypertension and hyperkalemia.
The characteristic sensitivity of Gordon’s patients to thiazide
diuretics is now explained by loss of the normal function of
WNK4 to suppress expression of the thiazide-sensitive cotransporter (NCCT) in the apical membranes of cells lining
the distal convoluted tubule; the resulting overexpression of
NCCT causes salt retention and hypertension. Mutant WNK4
also causes a deficit in surface expression of the ROMK K⫹
channel leading to impaired K⫹ secretion in the collecting
duct and hence hyperkalemia. The phosphorylation target(s)
for WNK4 are not known and only the WNK4-NCCT
interaction is definitely dependent on its kinase activity.
Identifying the phosphorylation target will be an important
direction for future research because WNK1 and WNK4 have
closest homology to STE20 kinases. This suggests they may
be involved in a mitogen-activated protein kinase signaling
pathway that regulates surface expression of NCCT, ROMK,
and probably other transporter molecules. However, phosphorylation is not the only effector mechanism for WNKs.
Like several other kinases, they have direct effects through
protein–protein interaction. In fact, the WNK4 mutations,
including the novel one described here (564D⬎H), cluster in
an acidic motif that is highly conserved across WNK1 and
WNK4. How this acidic motif is involved in protein–protein
interactions is an important and unresolved question.
Acknowledgments
This work was supported by grants from the British Heart Foundation (United Kingdom) and the Isaac Newton Trust (Cambridge,
UK). A.G. and G.C. have PhD studentships from the British Heart
Foundation and Medical Research Council (United Kingdom), respectively.
References
1. Paver W, Pauline G. Hypertension and hyperpotassaemia without renal
disease in a young male. Med J Aust. 1964;2:305–306.
2. Mansfield TA, Simon DB, Farfel Z, Bia M, Tucci JR, Lebel M, Gutkin M,
Vialettes B, Christofilis MA, Kauppinen Makelin R, Mayan H, Risch N,
Lifton RP. Multilocus linkage of familial hyperkalemia and hypertension,
pseudohypoaldosteronism type II, to chromosomes 1q31– 42 and 17p11q21. Nat Genet. 1997;16:202–205.
3. O’Shaughnessy KM, Fu B, Johnson A, Gordon RD. Linkage of Gordon’s
syndrome to the long arm of chromosome 17 in a region recently linked
to familial essential hypertension. J Hum Hypertens. 1998;12:675– 678.
4. Disse-Nicodeme S, Desitter I, Fiquet-Kempf B, Houot AM, Stern N,
Delahousse M, Potier J, Ader JL, Jeunemaitre X. Genetic heterogeneity of
familial hyperkalemic hypertension. J Hypertens. 2001;19:1957–1964.
5. Disse-Nicodeme S, Achard JM, Potier J, Delahousse M, Fiquet-Kempf B,
Stern N, Blanchard A, Guilbaud JC, Niaudet P, Chauveau D, Dussol B,
Berland Y, Dequiedt P, Ader JL, Paillard M, Grunfeld JP, Fournier A,
Corvol P, Jeunemaitre X. Familial hyperkalemic hypertension (Gordon
syndrome): evidence for phenotypic variability in a study of 7 families.
Adv Nephrol Necker Hosp. 2001;31:55– 68.
6
Hypertension
August 2005
Downloaded from http://hyper.ahajournals.org/ by guest on June 18, 2017
6. Disse-Nicodeme S, Achard JM, Desitter I, Houot AM, Fournier A, Corvol
P, Jeunemaitre X. A new locus on chromosome 12p13.3 for pseudohypoaldosteronism type II, an autosomal dominant form of hypertension.
Am J Hum Genet. 2000;67:302–310.
7. Wilson FH, Disse-Nicodeme S, Choate KA, Ishikawa K, NelsonWilliams C, Desitter I, Gunel M, Milford DV, Lipkin GW, Achard JM,
Feely MP, Dussol B, Berland Y, Unwin RJ, Mayan H, Simon DB, Farfel
Z, Jeunemaitre X, Lifton RP. Human hypertension caused by mutations in
WNK kinases. Science. 2001;293:1107–1112.
8. Mayan H, Vered I, Mouallem M, Tzadok-Witkon M, Pauzner R, Farfel Z.
Pseudohypoaldosteronism type II: marked sensitivity to thiazides, hypercalciuria, normomagnesemia, and low bone mineral density. J Clin Endocrinol Metab. 2002;87:3248 –3254.
9. Wilson FH, Kahle KT, Sabath E, Lalioti MD, Rapson AK, Hoover RS,
Hebert SC, Gamba G, Lifton RP. Molecular pathogenesis of inherited
hypertension with hyperkalemia: the Na-Cl cotransporter is inhibited by
wild-type but not mutant WNK4. Proc Natl Acad Sci U S A. 2003;100:
680 – 684.
10. Yang CL, Angell J, Mitchell R, Ellison DH. WNK kinases regulate
thiazide-sensitive Na-Cl cotransport. J Clin Invest. 2003;111:1039 –1045.
11. Kahle KT, Gimenez I, Hassan H, Wilson FH, Wong RD, Forbush B,
Aronson PS, Lifton RP. WNK4 regulates apical and basolateral Cl- flux
in extrarenal epithelia. Proc Natl Acad Sci U S A. 2004;101:2064 –2069.
12. Kahle KT, Wilson FH, Leng Q, Lalioti MD, O’Connell AD, Dong K,
Rapson AK, MacGregor GG, Giebisch G, Hebert SC, Lifton RP. WNK4
regulates the balance between renal NaCl reabsorption and K⫹ secretion.
Nat Genet. 2003;35:372–376.
13. Rungroj N, Devonald MA, Cuthbert AW, Reimann F, Akkarapatumwong
V, Yenchitsomanus PT, Bennett WM, Karet FE. A novel missense
mutation in AE1 causing autosomal dominant distal renal tubular acidosis
retains normal transport function, but is mis-targeted in polarized epithelial cells. J Biol Chem. 2004;279:13833–13838.
14. Gamba G, Miyanoshita A, Lombardi M, Lytton J, Lee WS, Hediger MA,
Hebert SC. Molecular cloning, primary structure, and characterization of
15.
16.
17.
18.
19.
20.
21.
22.
two members of the mammalian electroneutral sodium-(potassium)chloride cotransporter family expressed in kidney. J Biol Chem. 1994;
269:17713–17722.
Gordon RD, Ravenscroft PJ, Klem SA, Tunny TJ, Hamlet SA. A new
Australian kindred with the syndrome of hypertension and hyperkalemia
have dysregulation of atrial natriuretic peptide. J Hypertens. 1988;6:
S323–S326.
Gordon RD, Hodsman GP. The syndrome of hypertension and
hyperkalaemia without renal failure: long term correction by thiazide
diuretic. Scott Med J. 1986;31:43– 44.
Finer G, Shalev H, Birk OS, Galron D, Jeck N, Sinai-Treiman L, Landau
D. Transient neonatal hyperkalemia in the antenatal (ROMK defective)
Bartter syndrome. J Pediatr. 2003;142:318 –323.
Jeck N, Derst C, Wischmeyer E, Ott H, Weber S, Rudin C, Seyberth HW,
Daut J, Karschin A, Konrad M. Functional heterogeneity of ROMK
mutations linked to hyperprostaglandin E syndrome. Kidney Int. 2001;
59:1803–1811.
Boim MA, Ho K, Shuck ME, Bienkowski MJ, Block JH, Slightom JL,
Yang Y, Brenner BM, Hebert SC. ROMK inwardly rectifying ATPsensitive K⫹ channel. II. Cloning and distribution of alternative forms.
Am J Physiol. 1995;268:F1132–F1140.
Gamba G. Role of WNK kinases in regulating tubular salt and potassium
transport and in the development of hypertension. Am J Physiol Renal
Physiol. 2005;288:F245–F252.
Levy D, DeStefano AL, Larson MG, O’Donnell CJ, Lifton RP, Gavras H,
Cupples LA, Myers RH. Evidence for a gene influencing blood pressure
on chromosome 17. Genome scan linkage results for longitudinal blood
pressure phenotypes in subjects from the framingham heart study. Hypertension. 2000;36:477– 483.
Kamide K, Takiuchi S, Tanaka C, Miwa Y, Yoshii M, Horio T, Mannami
T, Kokubo Y, Tomoike H, Kawano Y, Miyata T. Three novel missense
mutations of WNK4, a kinase mutated in inherited hypertension, in
Japanese hypertensives: implication of clinical phenotypes. Am J
Hypertens. 2004;17:446 – 449.
A New Kindred With Pseudohypoaldosteronism Type II and a Novel Mutation (564D>H)
in the Acidic Motif of the WNK4 Gene
Amir P. Golbang, Meena Murthy, Abbas Hamad, Che-Hsiung Liu, Georgina Cope, William
Van't Hoff, Alan Cuthbert and Kevin M. O'Shaughnessy
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