From INSERM U358, Hôpital Saint-Louis (E.B., N.C., I.F., F.S.), and
INSERM U36, Collège de France (P.M., K.C., X.J., P.C., L.P.), Paris,
France.
Correspondence to Florent Soubrier, INSERM U358, Hôpital Saint-Louis, 1, Ave Claude Vellefaux, 75475 Paris, cedex 10, France. E-mail Soubrier{at}inserm.chu-stlouis.fr
Mutations in CYP11B1 lead to a hypertensive form of
congenital adrenal hyperplasia8 9 10 due to the
accumulation of 11-deoxycorticosterone and its metabolites, which have
mineralocorticoid activity. In contrast, mutations in
CYP11B2 lead to various forms of aldosterone
synthase deficiency, characterized by salt wasting and
hypotension.11 12 Furthermore, unequal
recombination between the 2 genes, leading to a duplicated hybrid
CYP11B gene, causes the dominantly inherited hypertensive
disorder of glucocorticoid-suppressible
hyperaldosteronism.5 13 14 In this disease, the
hybrid gene encodes an enzyme with aldosterone synthase
activity,14 which is expressed throughout the
adrenal cortex under the control of CYP11B1 regulatory
elements.3 Consequently, aldosterone
is improperly synthesized in the zona fasciculata/reticularis of the
adrenal cortex under the control of corticotropin.
It is possible that other mutations in these genes or in their
regulatory elements could also contribute to the genetic susceptibility
to essential hypertension. To test the genetic linkage of these genes
to essential hypertension, we carried out a genetic analysis of
this chromosomal region in 292 sibling pairs with essential
hypertension with the use of affected sib-pair
methods15 16 17 18 and a highly polymorphic
dinucleotide repeat identified in a P1 clone containing the
CYP11B1 gene.
We also performed a case-control study of 2 common polymorphisms in
the CYP11B2 gene. The first polymorphism (-344C/T)
involves a C/T substitution in a putative binding site for the
steroidogenic transcription factor SF-1.19
Previous studies have shown a 4-fold increase in binding of SF-1 to the
-344C allele, which could result in an altered transcription rate.
The second polymorphism is a common gene conversion in intron 2 of
CYP11B2, in which most of the intron is replaced by that of
CYP11B1.19 The association of these
two biallelic CYP11B2 polymorphisms was studied in 380
hypertensive individuals and 293 white controls.
Normotensive unrelated control subjects (n=293) were enrolled from
preventive medicine centers in Paris and Nancy. These controls had a
systolic blood pressure <145 mm Hg, a DBP <90 mm Hg, and
no history of antihypertensive treatment or chronic disease. All
individuals in the study were white. Clinical characteristics of the
study population are listed in Table 1
Isolation and Characterization of Dinucleotide
Repeat Polymorphism
Genotype Analysis of Dinucleotide
Repeat Polymorphism at the Human CYP11B1
Locus
Genotyping of CYP11B2 Polymorphisms
Analysis of the intron 2 polymorphism was carried out by
allele-specific PCR as follows. The samples were denatured at
94°C for 5 minutes, followed by 35 cycles at 94°C for 1 minute,
59°C for 1 minute, and 72°C for 1 minute followed by 1 cycle at
72°C for 10 minutes. Amplified products were electrophoresed in a
1.5% agarose gel and visualized by staining with ethidium bromide.
Oligonucleotides 5 (localized in intron 3 of
CYP11B1 and CYP11B2) and 6 (localized in intron 2
of CYP11B2) detected the nonconverted allele containing
the CYP11B2 sequence. Oligonucleotides 5 and
7 (localized in intron 2 of CYP11B1) detected the converted
allele, when it was present. DNA from subjects known to carry
the normal and converted alleles by sequencing were amplified as
positive controls.
Statistical Analysis
For the microsatellite marker and the 2 biallelic polymorphisms,
genetic linkage was tested by using 2 different affected sib-pair
methods (Table 3
The second method is based on the number of shared
(n1) and unshared (n2)
alleles among affected sib pairs computed from informative meioses.
When there are multiple sibs in a sibship, this method weights for the
number of pairs. Under the null hypothesis of no linkage, the numbers
of the shared and unshared alleles are equal to half of the
estimated sum of shared and unshared alleles
[(n1+n2)/2]. Under the
hypothesis of linkage, the number of shared alleles is greater than
the number of unshared alleles. A
In the case-control study of the 2 biallelic markers, comparisons of
genotype distributions and of allelic frequencies were assessed
by the
Members of 8 families from the Centre d'Etudes du Polymorphisme
Humain panel were genotyped for this marker. The genetic
location of the CYP11B1 gene was estimated with respect to
chromosome 8 markers in the Généthon map by multilocus
linkage analysis.22 These results showed
that the CYP11B1 gene lies in the interval between markers
AFMb014xe1 (D8S1744) and AFMa082wh9 (D8S1836) with odds >1000:1
(Figure 2
Linkage Study
The statistical analysis was also performed on subgroups of
families defined according to criteria used in previous
studies.20 23 24 These criteria included a body
mass index (BMI)
Association Study
A significant association with hypertension was found, however,
with the T allele of the promoter polymorphism of
CYP11B2 (-344C/T). The polymorphism -344C/T did not
exhibit significant deviation from Hardy-Weinberg expectations in the
case or control groups. A significant difference in genotype
(P=0.023) and allele (P=0.010) frequencies
was found between cases and controls. We also compared control subjects
and the subgroups of hypertensive subjects defined above. The
association remained significant in the subgroup with early-onset
hypertension (P=0.005) but was not significant when BMI was
This marker was used in a family study involving a large group
(n=167) of well-characterized white families with moderate to severe
essential hypertension present in at least 2 sibs. In addition to
these criteria, confounding factors such as obesity and diabetes or
ethnic heterogeneity were avoided. Statistical
analyses of the genotype data obtained in these 292 sib
pairs were performed with 2 different statistical methods. Both methods
are designed to test for an excess of concordance in the affected sib
pairs through the use of identity by descent. Both methods seem to have
similar power to detect linkage.25 The results
did not show any evidence for linkage to hypertension, in either the
whole panel or in family subsets selected for the severity or the early
onset of hypertension.
We also conducted a case-control study in 380 French hypertensive
patients and 293 normotensive control subjects who were
analyzed for the 2 frequent polymorphisms of the
CYP11B2 gene.19 We did not observe any
association of the intron 2 gene conversion with hypertension, since
the allele and genotype frequencies were similar in
hypertensives and normotensives. Conversely, the T allele of the
-344 polymorphism was significantly more frequent in hypertensives
(0.56) than in controls (0.48), suggesting an association of this
polymorphism with hypertension. Similar results were obtained by
comparing genotype frequencies between the 2 groups. We found a
significant association of the T allele with hypertension when
controls were compared with the most hypertensive person in each family
(P=0.023). This association was more significant when the
normotensives were compared with a subgroup with onset of hypertension
before the age of 45 years (P=0.005). In other hypertensive
subgroups the frequency of the T allele was also increased, but the
increase was not statistically significant (Table 4
In an independent study, Benetos et al27
observed a similar frequency of the -344T allele in a series of
216 white hypertensive patients (0.56). However, they reported an
association between the -344C allele and higher supine plasma
aldosterone levels and lower upright plasma renin levels;
an unexpected result, given the increased frequency of the T allele
in both hypertensive samples. In the present study we have no
information concerning the plasma aldosterone and plasma
renin levels of our population. To clarify these apparently conflicting
data, we genotyped a sample of 117 normotensive subjects for
whom serum aldosterone levels were available. In this
sample the -344T allele was associated with higher
(P<0.05) plasma aldosterone levels (data not
shown). The reasons for the difference between our sample and that of
Benetos et al are not evident.
Whether the -344C/T polymorphism represents a
functional variant of the CYP11B2 gene modulating the
expression of the gene is still a matter of debate. In gel shift assays
the -344C allele of the promoter binds the transcription factor
SF-1 4 times more than the -344T allele
does.19 The regulatory elements of the
CYP11B2 gene promoter, required for both basal and
angiotensin II or K+-stimulated
transcription, have been mapped in a study with serial deletion
mutants.28 A major element is located between
-129 and -114 and consists of an SF-1 and chicken ovalbumin upstream
promoter-1 binding site. Another major regulatory element is located
between -71 and -64 and is necessary for calcium induction of
CYP11B2 transcription. In contrast, the -344 region, which
was confirmed to bind SF-1 in the same study, did not seem to be
functionally relevant in their experiments. Hence, binding of SF-1 to
this site in vivo is not expected to lead to increased
CYP11B2 transcription and may in fact compete with the
functional sites for the transcription factor. Under these
circumstances the -344T allele, which has reduced affinity for
SF-1, would be associated with increased CYP11B2
transcription. The -344C/T polymorphism may be directly implicated
in transcriptional control in vivo, or it could be a marker for an
as-yet-unidentified polymorphism. In the latter case, the
identification of other polymorphisms in the regulatory regions of
the gene could be important.
There is an apparent discrepancy between the negative results
from the sib-pair study and the positive results in our association
study. We also observed discordant results between these 2 approaches
in analyses of the angiotensinogen
(AGT)20 23 and the type 1
angiotensin II receptor
(AGTR1)24 genes. Sib-pair studies are
considered to be more robust but to have lesser power than association
studies for detecting the implication of a locus in complex
diseases.29 A linkage analysis may be
more powerful if genetic heterogeneity is limited by
the selection of hypertensive cases based on their plasma levels of
aldosterone or K+. However,
biological measurements are often difficult to interpret in
hypertensives under medication. On the other hand, association studies,
while more powerful, may be the source of spurious associations when
the 2 samples are not drawn from the same population or when they
differ in ethnic origin. Indeed, White and
Slutsker19 previously reported significant
(P<0.001) racial differences in the frequencies of the 3
different CYP11B haplotypes (-344C/intron 2 without conversion;
-344T/intron 2 conversion; and -344T/intron 2 without conversion) by
comparing 168 white and 73 black schoolchildren. These ethnic
differences in allele frequencies of the -344C/T polymorphism
have also been observed between Africans and whites (X.J., unpublished
data). Consequently, although we took into account these possible
drawbacks during our enrollment of hypertensive and normotensive
individuals, it is important to replicate the positive results of
association with the -344T allele in independent studies.
It is also possible that the blood pressure effect of the
CYP11B2 gene is more prominent in subjects with a
high-sodium or low-potassium diet. To test this hypothesis, an
independent study population with sufficient information on dietary
electrolyte intake would be required.
In conclusion, although we found a significant association of the
aldosterone synthase gene with hypertension, our data do
not support a major role for this gene in hypertension, at least in
whites. In view of the importance of this gene in
aldosterone biosynthesis and hence in sodium and water
homeostasis, our results need to be compared with other independent
studies to define more precisely its implication in the development of
hypertension. The tools and the results presented in this study
might contribute to this goal.
Received January 21, 1998;
first decision February 12, 1998;
accepted March 20, 1998.
2.
Curnow KM, Tusie-Luna MT, Pascoe L, Natarajan R, Gu
JL, Nadler JL, White PC. The product of the CYP11B2 gene is
required for aldosterone biosynthesis in the human adrenal
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3.
Pascoe L, Jeunemaitre X, Lebrethon M-C, Curnow KM,
Gomez-Sanchez CE, Gasc J-M, Saez JM, Corvol P.
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Chua SC, Szabo P, Vitek A, Grzeschik KH, John M, White
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11.
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DH, Naiki Y, Kuribayashi I, Toda K, Hara T, Orii T, Yasuda K, Miura K,
Yamamoto Y, Imura H, Shizuta Y. Congenitally defective
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Lifton RP, Dluhy RG, Powers M, Rich GM, Cook S, Ulick
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Pascoe L, Curnow KM, Slutsker L, Connell JM, Speiser
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© 1998 American Heart Association, Inc.
Scientific Contributions
Structural Analysis and Evaluation of the Aldosterone Synthase Gene in Hypertension
![]()
Abstract
Top
Abstract
Introduction
Methods
Results
Discussion
References
AbstractAnomalies in either of the
tightly linked genes encoding the enzymes CYP11B1 (11ß-hydroxylase)
or CYP11B2 (aldosterone synthase) can lead to important
changes in arterial pressure and are responsible for
several monogenically inherited forms of hypertension. Mutations in
these genes or their regulatory regions could thus contribute to
genetic variation in susceptibility to essential hypertension. To test
this hypothesis, we performed 2 complementary studies of the
CYP11B1/CYP11B2 locus in essential
hypertension. After characterizing a DNA contig containing the
CYP11B1 gene and mapping the gene in the Centre
d'Etudes du Polymorphisme Humain reference panel of families, we
performed a linkage study with 292 hypertensive sibling pairs and a
highly informative microsatellite marker near CYP11B1.
We also analyzed the association of 2 frequent biallelic
polymorphisms of the CYP11B2 gene, 1 in the promoter
at position -344 (-344C/T) and the other, a common gene conversion in
intron 2, with hypertension in 380 hypertensive patients and 293
normotensive individuals. Statistical analyses did not show
significant linkage of the CYP11B1 microsatellite marker
to hypertension. No positive association with hypertension was found
with the gene conversion in intron 2, but a positive association with
hypertension was found with the -344T allele. The hypertensive and
normotensive samples differed significantly in both genotype
(P=0.023) and allele frequencies
(P=0.010). Our data suggest a modest contribution of the
CYP11B2 gene to essential hypertension.
Key Words: aldosterone synthase steroid 11ß-hydroxylase biallelic polymorphism microsatellite marker association study linkage study
![]()
Introduction
Top
Abstract
Introduction
Methods
Results
Discussion
References
The cytochrome P450,
CYP11B1, a steroid 11ß-hydroxylase, catalyzes the terminal step of
cortisol biosynthesis.1 2 The enzyme is expressed
at high levels throughout the human adrenal
cortex3 and is positively regulated by
corticotropin.2 A related enzyme, CYP11B2
(aldosterone synthase), also has steroid 11ß-hydroxylase
activity as well as the 18-hydroxylase and 18-oxidase activities
required for the terminal steps of aldosterone
biosynthesis.1 2 Expression of this enzyme is
limited to the adrenal zona glomerulosa, where it is principally
regulated by serum levels of potassium and angiotensin II.
The two genes encoding these enzymes are located on chromosome 8q22
40 kb apart.4 5 6 Each gene contains 9 exons
and extends over >8000 bp of DNA.7 The
nucleotide sequences of these genes are 95% identical in
coding regions and
90% identical in introns, whereas the encoded
proteins are 93% identical in their predicted amino acid
sequences.
![]()
Methods
Top
Abstract
Introduction
Methods
Results
Discussion
References
Study Population
This study was approved by a local review committee, and all
subjects gave informed consent. A total of 380 hypertensive cases were
selected in 3 collaborating centers in France (Paris, Toulouse, and
Bordeaux) according to the following criteria20:
(1) onset of hypertension at <60 years of age;
(2) established hypertension as defined by either a
diastolic blood pressure DBP >90 mm Hg in treated
patients or a DBP >95 mm Hg on 2 consecutive visits for those
untreated; (3) the absence of secondary forms of
hypertension, as determined by appropriate clinical investigation in
the collaborating center; and (4) families with
at least 2 siblings affected by hypertension. Subjects with a history
of alcohol intake >50 g/24 h, oral contraceptive therapy, diabetes
mellitus, or renal impairment were excluded. Blood pressure was
measured in the supine position with a sphygmomanometer. Application of
these criteria led to the ascertainment of 170 sibships in which 2 or
more offspring were hypertensive (125 pairs, 37 trios, 6 quartets, and
2 quintets). A total of 292 affected sibling pairs were thus
evaluated.
.
View this table:
[in a new window]
Table 1. Clinical Parameters of Study
Population
A P1 clone containing the human CYP11B1 gene was
obtained from a human foreskin fibroblast library by polymerase chain
reaction (PCR) screening of clone pools and the use of
oligonucleotides 5 and 6 (Table 2
) (reference DMPC-HFF No. 129F1, Genome
Systems). Screening of the same library with the corresponding
oligonucleotides from CYP11B2 did not yield
any positive clones. Sublibraries of EcoRI,
BamHI, and Sau3A restriction fragments from the
P1 clone were then constructed in a pKS Bluescript vector (Stratagene),
and individual colonies were replicated onto nylon filters for later
screening with oligonucleotide probes. The ends of some
randomly obtained clones were sequenced, and radioactively labeled
oligonucleotide probes from these sequences and from
the CYP11B1 gene were used to identify overlapping clones.
By repeating this hybridization strategy, combined with sequencing of
the ends of subsequently identified overlapping clones and standard
restriction enzyme mapping of subclones, a contig surrounding the
CYP11B1 gene was constructed (Figure 1
). Clones containing
dinucleotide repeats were identified by hybridization with
a (CA)15 oligonucleotide probe.
These clones were sequenced, and oligonucleotides
flanking the repeat sequence (oligonucleotides 8 and 9
of Table 2
) were made to amplify this polymorphic region in genomic
DNA. Initial studies showed this marker to be highly polymorphic,
with a heterozygosity of 72%.
View this table:
[in a new window]
Table 2. Amplimers and Allele-Specific Oligonucleotides Used
to Detect Variants of CYP11B1 and CYP11B2 Genes
and for PCR Screening of a Human P1
Library

View larger version (17K):
[in a new window]
Figure 1. Diagram of contig containing
CYP11B1 gene. Genomic sequence is
represented by a line, with BamHI (
) and
EcoRI (
) restriction sites indicated above and below
the line, respectively. Shaded boxes above the sequence
represent fragments that were subcloned into pBluescript
vector; the CYP11B1 gene is represented by a solid
rectangle and the dinucleotide repeat by an open box. Long
interspersed repeat elements (LINE-1) were found just upstream of
CYP11B1 as well as 3' from it (not shown). Expanded
sections of dinucleotide repeat, CYP11B1,
and CYP11B2 (which lies 40 kb 5' from
CYP11B1) genes show positions of
oligonucleotides used for genotyping, intron-exon
structure of the 2 CYP11B genes, and positions of
polymorphisms studied.
The CYP11B1 dinucleotide repeat
genotypes were determined by PCR amplification of genomic DNA
with [
-32P]ATP end-labeled primers
(oligonucleotides 8 and 9 of Table 2
) flanking the CA
repeat and subsequent analysis by denaturing
acrylamide gel electrophoresis. Allele identity was
checked in all gels by comparison with a control DNA. Population
allele frequencies of the CYP11B1 microsatellite were
estimated from the families by using the ILINK program.
The genomic region encompassing the biallelic polymorphism
(-344C/T) was amplified by using oligonucleotide
primers 1 and 2 shown in Table 2
. The amplification was performed with
100 ng of DNA in a total volume of 50 µL containing 10 mmol/L
Tris HCl (pH 9), 50 mmol/L KCl, 1.5 mmol/L
MgCl2, 0.1% Triton X-100, 0.2 mg/mL BSA,
200 µmol/L dNTPs, 25 pmol of each primer, and 0.2 U
Taq polymerase (ATGC Biotechnologie). The samples were
denatured at 94°C for 5 minutes, followed by 35 amplification cycles
at 94°C for 30 seconds, 52°C for 30 seconds, and 72°C for 30
seconds and 1 cycle at 72°C for 10 minutes. After enzymatic
amplification, one fifth of the PCR product was denatured in 150
µL of 0.5 mol/L NaOH and 1.5 mol/L NaCl and blotted onto nylon
membranes (N+, ICN). Membranes were then neutralized in 2x SSC and
cross-linked with UV light. Genotyping was performed by using
allele-specific
oligonucleotides.21 Each membrane
was hybridized in 7% polyethylene glycol10% SDS at 50°C for 4
hours with 100 pmol of either of the 2 oligonucleotides
(3 and 4, Table 2
) end labeled with
[
-32P]ATP. The membranes were washed twice
at room temperature in 1x SSC for 5 minutes followed by 5 minutes in
0.5x SSC at 52°C, followed by autoradiography.
The frequencies of the 13 alleles of the microsatellite
marker were estimated from all pedigrees collected with the use of the
ILINK program of the LINKAGE package (0.001,
0.007, 0.298, 0.414, 0.082, 0.045, 0.050, 0.029, 0.060, 0.004, 0.003,
0.003, and 0.003). The frequency of the -344T allele (0.546) and
of the intron 2 conversion (0.446) was evaluated with the same
program.
). The first is based on
the Haseman-Elston sib-pair method.15 16 It
consists of estimating the proportion of alleles shared by affected
sib pairs identical by descent at the marker locus. Marker information
on other sibs and 1 or both parents was incorporated when available. A
1-sided t test with (n-1) df (where n is the
total number of affected sib pairs) was performed to determine whether
this mean proportion was >0.5 (the expected value under the null
hypothesis of no linkage). The result of this test was obtained by
using the program SIBPAL of the SAGE
package.17
View this table:
[in a new window]
Table 3. Linkage Analysis With CYP11B1 Microsatellite Marker and 2 Biallelic Polymorphisms of
CYP11B2 in Hypertensive Sibships by 2 Different Methods
(SAGE and
ANALYZE)
2 test
with 1 df is computed to compare the observed and expected
values. This statistic can be computed in the program
SIBPAIR of the ANALYZE
package.18
2 test with 2 and 1 df,
respectively. Deviation from Hardy-Weinberg equilibrium was tested by
the
2 test with 1 df.
![]()
Results
Top
Abstract
Introduction
Methods
Results
Discussion
References
Localization of CYP11B1 Gene and Identification of
Flanking Microsatellite Markers
A 60-kb contig of subclones containing the CYP11B1 gene
was assembled as set out in the Methods section. A BamHI,
EcoRI restriction site map of this contig is
presented in Figure 1
. A dinucleotide repeat was
identified in the 3'-flanking region of the CYP11B1 gene.
The entire coding region of the CYP11B1 gene was isolated on
a single BamHI fragment of 8.5 kb. The surrounding sequence
included a truncated long interspersed repeat element (LINE-1) 400 bp
5' from the transcription start site, suggesting that the most
important promoter elements lie close to the gene as well as another
LINE element farther 3' from the gene. An open reading frame with
>95% sequence homology to an expressed sequence tag (EST) from a
human brain cDNA library was also found 3' from the gene in the P1
clone (data not shown). Genotypes of our patients at the
polymorphic microsatellite locus were determined by PCR
amplification and acrylamide gel electrophoresis.
).

View larger version (14K):
[in a new window]
Figure 2. Line graph shows location (log of the odds [lod]
score) for placement of the CYP11B1 locus with respect
to chromosome 8 markers characterized in the Centre d'Etudes du
Polymorphisme Humain (Paris, France) reference families. Maximum
likelihood placement (maximum of log of the odds score curve) for
CYP11B1 is indicated by the arrow. Odds against
alternative orders are also indicated. Distances along the
x axis are in centimorgans (cM).
Because parental genotypes were generally not available,
allele frequencies were estimated by the ILINK program
(LINKAGE) of the total group of families. Results of
linkage analysis with the CYP11B1 microsatellite
marker and the 2 biallelic polymorphisms of CYP11B2
(-344C/T and intron 2 conversion) in hypertensive sibships are shown
in Table 3
. No significant excess of shared alleles was observed in
the whole panel by using either of the programs for sib-pair
analysis; the calculated number of alleles shared was close
to 0.5 in each case.
27 kg/m,2 severe hypertension
(DBP
100 mm Hg or
2 antihypertensive treatments), or an early
age of onset (<45 years of age). Application of these criteria,
isolated or in combination, did not result in any significant evidence
for linkage.
An association study was performed by comparing allele and
genotype frequencies for the 2 biallelic polymorphisms of
CYP11B2 (-344C/T and intron 2 conversion) in hypertensive
patients (n=380 and n=369) and normotensive control subjects (n=293 and
n=277). We did not observe significant differences between the 2 groups
for the intron 2 conversion. The frequency of the gene conversion in
our patients was 0.45 in hypertensives and 0.43 in normal controls
(
2=0.66, P=0.41).
27 kg/m,2 suggesting
heterogeneity in the cause of hypertension in these
patients (Table 4
).
View this table:
[in a new window]
Table 4. Comparison of Allele and Genotype Frequencies (Freq)
of C -344T Polymorphism in Controls and Hypertensive
Cases
![]()
Discussion
Top
Abstract
Introduction
Methods
Results
Discussion
References
Several lines of argument designate the
aldosterone synthase gene as a major candidate gene for
predisposition to hypertension. These arguments are drawn from the
biochemical role of aldosterone synthase and from the
occurrence of major blood pressure disorders due to abnormalities of
this gene. We specifically developed genetic tools to investigate the
role of the aldosterone synthase gene in human essential
hypertension and also used previously described markers having a
potential functional effect on the regulation of this gene. A highly
polymorphic microsatellite marker was identified at 8 kb in the 3'
region of the CYP11B1 gene, located
40 kb from the
CYP11B2 gene. This marker was used to map the
CYP11B gene between markers D8S1744 and D8S1836 on the long
arm of chromosome 8.
). When the
analysis was limited to those with a BMI
27
kg/m2, the association was not significant,
suggesting involvement of the allele in a common mechanism leading
to increased BMI and hypertension. The existence of such a common
mechanism would be consistent with the known effect of excess
mineralocorticoid activity, which leads to salt and water retention and
hypervolemic hypertension.26
![]()
Acknowledgments
Dr Brand is supported by the Deutsche Forschungsgemeinschaft
(DFG, Br 1589/11) and the Société Française
d'Hypertension Artérielle. Dr Pascoe was supported by a grant
from the Fondation Pour la Recherche Medicale and the IPSEN foundation
for therapeutic research.
![]()
References
Top
Abstract
Introduction
Methods
Results
Discussion
References
1.
Kawamoto T, Mitsuuchi Y, Toda K, Yokoyama Y,
Miyahara K, Miura S, Ohnishi T, Ichikawa Y, Nakao K, Imura H, Ulick S,
Shizuta Y. Role of steroid 11ß-hydroxylase and steroid
18-hydroxylase in the biosynthesis of glucocorticoids and
mineralocorticoids in humans. Proc Natl Acad Sci
U S A. 1992;89:14581462.
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