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Original Studies |
Service d’Endocrinologie et Maladies Métaboliques (P.C., A.B.), CHU Rangueil, 31403 Toulouse; Endocrinologie Cellulaire et Moléculaire de la Reproduction (S.C., R.C., M.-L.K.), URA Centre Nationale de la Recherche Scientifique 7080, Université Pierre and Marie Curie, 75006 Paris; Service d’Endocrinologie et des Maladies de la Reproduction (S.C.-M., P.B., M.-L.K.), Hôpital Saint-Antoine, 75012 Paris; INSERM U342 (N.L., M.-L.K.), Hôpital Saint-Vincent-de-Paul, 75014 Paris; Service de Biochimie Médicale (M.-L.K.), Hôpital Pitiè-Salpetrière, 75013 Paris, France
Address all correspondence and requests for reprints to: Philippe Caron, M.D., Service d’Endocrinologie, CHU Rangueil, 1 Avenue J. Poulhès, 31403 Toulouse Cedex, France.
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Abstract |
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 Top Abstract IntroductionSubjects and MethodsResultsDiscussionReferences |
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-subunit
significantly increased in all patients during the pulsatile GnRH
administration. Thus, these hypogonadal patients are partially
resistant to pulsatile GnRH administration, suggesting that they should
be treated with gonadotropins to induce spermatogenesis or ovulation
rather than with pulsatile GnRH. |
Introduction |
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TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
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This report describes a family with three siblings suffering from isolated hypogonadotropic hypogonadism caused by compound heterozygous mutations in the GnRHR gene. All the affected subjects gave an incomplete and variable response of gonadotropin secretion to iv pulsatile GnRH administration, suggesting that mutations in the GnRHR gene are responsible for a variable degree of resistance to GnRH.
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Subjects and Methods |
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TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
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The family is described in Fig. 1
. The two brothers (II1 and II2) were
referred for evaluation of sexual infantilism at ages 22 and 20,
respectively. They had had microphallus and bilateral cryptorchidism.
Patient II1 underwent right orchidectomy at age 5. Physical examination
revealed the absence of facial hair and sparse pubic hair, and both
patients had a testicular vol of 3 mL or less. Their body mass indexes
were 32.8 and 23.3 kg/m2, and both brothers had bilateral
gynecomastia. The sister (II3) had primary amenorrhea and complete
impuberism at age 17; her breast development was Tanner stage 1.
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) established the diagnosis of isolated
hypogonadotropic hypogonadism. The two brothers were treated with oral
testosterone undecanoate (Pantestone, 40 mg, t.i.d.;
Organon, Puteaux, France), whereas their sister was given
estrogen- and progestin-replacement therapy.
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). The mother (I2) had a normal puberty at age
14, had irregular menses, and underwent hysterectomy at age 43. There
was no indication of parental consanguinity. Written informed consent
for genetic and clinical studies was obtained from all the
subjects. Methods
In vitro studies
Preparation of genomic DNA and DNA sequencing
Genomic DNA was isolated from peripheral blood cells using a
proteinase K-phenol-chloroform procedure. DNA was amplified by PCR
using sets of primers based on the DNA sequences deposited with
EMBL/GenBank data libraries under accession numbers Z99760, Z99761, and
Z99995. Products were purified on Microcon-30 columns (AMICON, Beverly,
MA) and sequenced directly using the AmpliTaq dye Terminator Cycle
Sequencing kit and an ABI PRISM 377 DNA sequencer (Perkin-Elmer Corp., Roissy, France). The creation or the loss of restriction
sites by each of the two mutations was used to confirm the presence of
the mutations and to identify family members as carriers of the mutated
alleles. PCR products were digested with appropriate enzymes, according
to the recommendations of the manufacturers. Digested fragments were
separated by electrophoresis on agarose or polyacrylamide gels,
depending on their predicted size.
Construction of wild-type and mutant GnRHR complementary DNA (cDNA)
expression vectors
The full-length, wild-type GnRHR cDNA was synthesized by RT of
GnRHR messenger RNA extracted from a normal pituitary gland (9) and
cloned into PGEM-T easy vector (Promega Corp.,
Charbonnières, France). PCR products from the genomic
DNA-containing mutations were cloned into the PGEM-T easy
vector, and mutant cDNAs were constructed by exchanging the wild-type
DNA segment with the mutated one. Both wild-type and mutated cDNAs were
subcloned into pmol/LSG-CAT/Amp eukaryotic expression vector
(Pharmacia Biotech, Orsay, France). The entire sequences
of the cloned receptors were verified; they were identical to that of
the published GnRHR, except for a synonymous A975T substitution and the
expected mutations in the mutant clones.
Functional studies of the GnRHR in Chinese hamster ovary
cells
CHO-K1 cells were cultured in six-well plates at
9.104 cells per well, in Ham-F2 containing 100 µg/mL
gentalline (Sigma Chemical Co., Saint Quentin Fallavier,
France) and 8% newborn calf serum at 37 C. Monolayer cultures
(60–70% confluence) were transiently transfected with either the
wild-type or the mutant human GnRHR cDNA cloned into pmol/LSG using
lipofectamine reagent (Gibco BRL, Life Technologies, Gaithersburg, MD). Briefly, purified DNA (1.2–4.8
µg) was diluted in opti-MEM solution (Gibco BRL), and
the mixture was combined with Lipofectamine (24 µg in opti-MEM).
Cells were incubated with the complexes for 5 h at 37 C in a
CO2 incubator. The medium was replaced with fresh complete
growth medium, and the cultures were maintained for 60 h to allow
synthesis of the receptors before binding and functional assays. All
assays were performed on at least three independent experiments, and
values are means of duplicate determinations. Total RNA was extracted
from the transfected cells (10) using RNA-PLUS (Bioprobe Systems,
Montreuil, France), and contaminating DNA was eliminated by digestion
with ribonuclease-free deoxyribonuclease I (Gibco BRL).
Expression of wild-type and mutant GnRHR genes was studied by dot-blot
hybridization using 32P-cDNA GnRHR as probe (9).
Receptor binding assays
[His5, D-Tyr6]GnRH, kindly provided by
Dr. R. Millar (Cape Town, South Africa), was iodinated with
125I by the chloramine-T method, and the labeled ligand was
purified on a Sephadex G-25 column. Specific activity was determined by
self-displacement analysis using a rat pituitary membrane receptor
assay (11). For displacement analysis, cells were incubated with
125I[His5, D-Tyr6]GnRH (0.5
nmol/L), and increasing amounts of unlabeled peptide for 75 min at room
temperature. They were washed twice with ice-cold PBS and solubilized
in 0.2 mol/L NaOH-0.1% SDS. Incorpored radioactivity was then
measured. Data from displacement analysis were used to derive
equilibrium constants by Scatchard plots.
Inositol phosphate (IP) production
Transfected CHO-K1 cells were incubated for 48 h, to ensure
receptor gene expression, and then labeled overnight with
myo-[2-3H]inositol (6 µCi/mL; Amersham, Les Ulis,
France) in an inositol-free (RPMI, Gibco BRL, Life Technologies)
medium containing 20 mmol/L LiCl. Cells were washed twice with Hank’s
medium, containing 0.1% BSA and 20 mmol/L LiCl, and incubated for
1 h at 37 C in the same solution with or without 10-7
mol/L GnRH. Reactions were stopped with ice-cold perchloric acid (5%
final concentration). Phosphoinositides (IPs) were extracted and
separated by anion-exchange resin (12), and the incorpored
radioactivity was measured in duplicate samples.
In vivo studies
Protocol
Baseline hormone concentrations were measured 16 and 25 days
after the withdrawal of androgen or estrogen and progestin replacement
therapy. The patterns of spontaneous LH secretion of the father and the
three children were then assessed. A catheter was placed in a forearm
vein of each patient, and 4-mL samples of blood were taken every 10
min, for 5–8 h, starting at 0800 h. The samples were collected in
EDTA tubes and centrifuged, and the plasma was stored at -20 C until
assayed.
Pulsatile GnRH was given using a closed iv system (Zyklomat pulse, Lutrelef 3.2 mg, Ferring SA, Gentilly, France). GnRH pulses were given every 90 min. The dose was 10 µg/pulse for 40 h for all the children. In patient II3, a dose of 20 µg/pulse was subsequently administered for 24 h.
The patterns of GnRH-induced LH and free -subunit secretion were
evaluated by measuring the hormones in the 10-min plasma samples taken
for a 6–8 h period during pulsatile GnRH administration. Plasma
steroid (testosterone, 17ß estradiol), FSH, and inhibin
concentrations were measured before and after pulsatile GnRH
administration.
The gonadotropin (LH, FSH) response to GnRH was tested by iv injection of 100 µg GnRH (Roussel Lab, Paris, France) before and after the pulsatile GnRH administration. Blood samples were taken immediately before, and 30 and 60 min after GnRH injection.
Assays
LH concentrations were determined using an immunoradiometric
assay (IRMA) (125I-hLH Coatria; BioMerieux,
Marcy-l’Etoile, France). The between-assay coefficient of variation
(CV) was 5.2% when the mean LH was less than 7 IU/L. The within-assay
CV was less than 4.0%. The detection limit for LH was 0.4 IU/L. The LH
concentration was expressed in terms of International Standard for LH
immunoassay IRP (International Reference preparation) 68/40. The
normal range was 1–8.5 IU/L in men and 2–11 IU/L in early follicular
phase. Free -subunit concentrations were measured using -subunit
IRMA (Immunotech, Marseille, France), with a between-assay
CV of less than 10.5% and a within-assay CV of less than 6.5%. The
cross-reactivity of LH and FSH in the -subunit assay was less than
0.1%. All samples from individual subjects were run in duplicate in
the same assay. FSH was determined by an IRMA (125I-human
FSH Coatria, BioMerieux). The between-assay CV was less than 4%; the
within-assay CV was 2.8%. The FSH concentration was expressed in terms
of International Standard for FSH immunoassay International Reference
preparation 78/549. The normal range was 1.2–11 IU/L in men,
and 1.3–11.1 IU/L in early follicular phase. RIAs were used to
measure testosterone: Dina-testok, Sorin Biomedica, Saluggia, Italy
(within-assay CV = 9%, between-assay CV = 10%, detection
limit = 0.18 nmol/L, normal range in men: 9.7–28.4 nmol/L) and
estradiol: Estradiol-2, Sorin Diagnostics, Antony, France
(within-assay = 4.2%, between-assay = 4.9%, detection
limit = 18 pmol/L, normal range in early follicular phase: 70–220
pmol/L). Inhibin B was measured by an enzyme-linked immunosorbent assay
(Serotec, Oxford, UK). Inhibin A had a 1%
cross-reactivity in this assay. Intraassay precision was 7.4% at 44
pg/mL and 4.2% at 225 pg/mL. The normal range is 70–330 pg/mL in men
and 10–300 pg/mL in the early follicular phase.
LH pulse analysis
LH pulse analysis was performed using Cluster analysis
(13) with method number 7, which calculates the SD as a
power function of the LH concentrations, based on series of duplicates.
We selected the optimal parameter for LH male data (J. D.
Veldhuis, Correspondence of all users of Cluster analysis, 24 October
1988). These parameters are reported to give minimal false positive and
false negative error rates (<5%). The half-life of immunoreactive LH
was estimated using the Expfit program (version 1.6) (V. Guardabasso,
P. J. Munson, D. Rodbard), applied to the downstroke of every
significant pulse identified by the Cluster analysis algorithm. The
Expfit program was run using one exponential term for each downstroke,
which allowed us to calculate the rate constant (R). The half-life was
determined as a Napierian logarithm of 2/R. The apparent
half-life of LH in each patient was the mean of values for all
identified LH pulses.
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Results |
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TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
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DNA sequencing and haplotyping of the GnRHR gene. Two germline
mutations were found in all three siblings with hypogonadotropic
hypogonadism (Figs. 1 and 2). Exon 1
contained a cytosine to adenine (C to A) mutation at position 386,
resulting in alanine being replaced by aspartate at residue 129
(A129D). This residue is part of the third transmembrane domain (TM3)
of the receptor. Exon 3 contained a guanine to adenine (G to A)
mutation at position 785, resulting in the replacement of arginine by
glutamine at peptide position 262 (R262Q), in the third intracellular
loop. The mutation at position 386 led to the loss of a CviJ
restriction site, whereas mutation at position 785 generated a new
restriction site for AluI. Segregation analyses, using
restriction site enzymatic digestion plus sequencing, traced each
mutant to one of the parents. The heterozygous state of each parent was
confirmed by the presence of only one mutation (R262Q for the father,
A129D for the mother), indicating that the patients had inherited
germline mutations and were compound heterozygotes.
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shows radioligand displacement curves
(A) with [His5, D-Tyr6] GnRH and IP
production (B) in CHO cells producing wild-type or mutant (A129D)
GnRHRs. The wild-type receptor had high-affinity binding [dissociation
constant (Kd) = 1.6 ± 0.4 nmol/L], and GnRH
(10-7 mol/L) caused a 7-fold increase in total IP
production. In contrast, the A129D mutant had neither measurable
binding nor any IP production.
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The basal hormone profiles of the parents and the three siblings
are shown in Table 1. Except for the gonadotropin deficiency in the
three siblings, all the results for pituitary, thyroid, and adrenal
functions were normal. Sex steroid and gonadotropin concentrations,
measured 16 and 25 days after withdrawal of androgen or estrogen and
progestin replacement therapy, were similar to those reported at
diagnosis. The ferritin concentration was also normal.
Patterns of endogenous LH and free -subunit secretions (Fig. 4, Table 2). All the affected siblings had
serum LH and FSH concentrations below the normal adult range. The two
brothers (II1 and II2) had two and three spontaneous LH pulses
during the sampling period. The LH pulses were of abnormally low
amplitude (0.34 ± 0.17 and 0.15 ± 0.03 IU/L). The mean peak
amplitudes were significantly different from that of the normogonadic
father (2.39 ± 0.73 IU/L). The endogenous LH secretory pattern of
their sister (II3) completely lacked any apparent LH pulse. The
patterns of spontaneous free -subunit secretion varied with low
levels in patients II1 and II3 (Fig. 5),
and significant erratic secretion in patient II2. Inhibin B levels were
low or normal in the two brothers and were undetectable in their
sister.
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, Table 2).
iv pulsatile GnRH administration (10 µg/pulse), at a dose of 90
ng/kg·pulse (patient II1) and 115 ng/kg·pulse (patient II2),
increased the mean LH concentrations in both patients (patient II1:
from 1.16 ± 0.03 to 1.58 ± 0.03 IU/L; patient II2: from
0.82 ± 0.01 to 2.33 ± 0.08 IU/L) (P <
0.01). However, each pulse of exogenous GnRH was not associated with a
pulse of LH. The mean LH peak amplitude did not increase in patient II1
(0.34 ± 0.1 IU/L), whereas it did increase in patient II2
(1.11 ± 0.63 IU/L). The half-lives of immunoreactive LH decreased
significantly in these patients during the pulsatile GnRH
administration (patient II1: before, 395; during GnRH, 230 min)
(patient II2: before, 374; during GnRH, 153 min) but remained longer
than the value in the normotestosteronemic father (LH half-life, 123
min). The plasma testosterone levels had not changed significantly
after 40 h of pulsatile GnRH, and they remained at prepubertal
values. Inhibin B concentrations did not change significantly in
patient II1 and increased in patient II2 during pulsatile GnRH.
Patient II3 was given 40 h of pulsatile GnRH (10 µg/pulse at
90-min intervals), for a pulse dose of 133 ng/kg; but her LH secretory
profile remained apulsatile, with LH less than 0.4 IU/L (Fig. 5). The
GnRH dose was increased to 20 µg/pulse every 90 min for 24 h,
which resulted in the appearance of a pulsatile LH pattern: each
exogenous GnRH pulse triggered an LH response of low amplitude
(0.16 ± 0.01 IU/L). The estradiol levels did not increase in this
patient, and they remained in the prepubertal range throughout the
pulsatile GnRH administration.
All the patients showed a small, but detectable, rise in circulating
FSH concentrations in response to the pulsatile GnRH administration,
and their mean free -subunit levels also increased. Patient II3
showed a significant increase in free -subunit (234 ± 8 mU/L,
P < 0.01) after 40 h of 133 ng/kg·pulse of
GnRH, whereas her LH secretory profile remained apulsatile (Fig. 5). At
the end of the pulsatile GnRH administration, the plasma LH and FSH
concentrations increased significantly, after iv injection of 100 µg
GnRH; and the amplitudes of the responses in patients II1 and II2 were
greater than before pulsatile GnRH.
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Discussion |
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TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
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-subunit and gonadotropins (LH, FSH). The GnRHR cDNA has been
cloned (14, 15), and its gene is located on the long arm of chromosome
4 between markers D4S392 and D4S409 (16). The coding region is
distributed among 3 exons separated by two large introns (17). Rare
missense mutations of the GnRHR gene have been recently reported in
hypogonadic patients (6, 7). In vitro studies had revealed
abnormal biological activity of the mutated GnRHRs caused by decreased
GnRH binding and/or reduced GnRH stimulation of IP3 production. This report describes a family in which three of the siblings suffer from hypogonadotropic hypogonadism associated with R262Q and A129D mutations in the GnRHR gene. All the affected siblings are compound heterozygotes for these mutations, and thay have inherited a different mutation in the GnRHR gene from each parent. The disorder was transmitted as an autosomal recessive trait.
This is the first description of the A129D mutation in TM3 of the GnRHR. In vitro expression studies showed that this mutation results in the complete loss of ligand binding, resulting in no GnRH-induced IP3 production. Byrne et al. (18) used site-directed mutagenesis of the GnRHR to show that the Met125 within TM3 is important for ligand binding, and that some other residues in TM3 contribute to binding. Mutations in TM3 have also been described for other G-protein-coupled receptors. An inactivating A118T mutation of the TRH receptor gene was recently described (19), and the mutated receptor bound TRH very poorly, much like our finding. When amino-acid are aligned according to the consensus numbering scheme of Probst et al. (20), the A3.40(129) corresponds to V3.40(509) for the TSH receptor and I3.40(122) for the dopamine D2 receptor. I3.40(122) was exposed in the binding crevice, and thus might interfere with dopamine binding (21). Because the A129D mutation replaces a neutral residue with an acid one in TM3, it might affect electrostatic or hydrogen bond interactions with adjacent helices, or alter the molecular configuration of the receptor. It is also possible that loss of receptor function may be caused by altered transport to the cell surface. However, dot-blot hybridization of RNA confirmed that wild-type and mutant receptor genes are expressed at similar levels.
The R262Q mutation in the intracellular loop 3 of the receptor has been previously described in patients with isolated hypogonadotropic hypogonadism (6, 7). In vitro expression studies showed that this mutated receptor binds GnRH with a normal Kd, but a 10- to 50-fold increase in the amount of GnRH agonist is needed to induce a 50% maximal increase in IP3 production. Site-directed mutagenesis of the GnRHR has also shown that the Ala residue at position 261, near R262, does not affect ligand binding but is critical for binding of the receptor to (and/or activation of) the G-protein (22).
Most of the patients who reported (6, 7) have the same R262Q mutation in the third intracellular loop of the receptor, but the mutation in the second allele is different. In vitro studies have shown that Q106R (6) leads to a partial loss of function, whereas Y284C (7) results in a dramatic decrease in signal transduction, and A129D abolishes GnRH-induced IP3 production in our patients. Therefore, the in vitro studies suggest that the biological activity of the mutated GnRHR is affected to a greater degree in this family than in other hypogonadic patients with mutations in the GnRHR gene.
The phenotypic spectrum of isolated hypogonadotropic hypogonadism in patients with mutations in the GnRHR gene seems to vary. The propositus of the family described by de Roux et al. (6) underwent puberty at the age of 16 yr and was referred for evaluation of incomplete hypogonadism 6 yr later, indicating that hypogonadism may be partial in subjects with mutations in the GnRHR gene. Patients II1 and II2 had microphallus and cryptorchidism, implying that gonadotropin secretion had been deficient in utero. They were referred for evaluation of lack of puberty, whereas their sister presented primary amenorrhea and impuberism. The differences in the phenotype are also obvious from the hormone profiles, with basal serum LH and FSH concentrations, which are GnRH dependent, in the upper part of the normal range in the affected patient described by de Roux et al. (6); whereas the basal gonadotropin concentrations were low-normal in patients reported by Layman et al. (7), and they are below normal in the subjects we have studied. The secretory pattern of gonadotropin in our affected siblings revealed a low-normal LH pulse frequency, with a decreased amplitude in subjects II1 and II2, as reported by de Roux et al. (6), and a complete absence of any LH pulse in their sister (II3). None of the three subjects showed any increase in basal LH interpulse frequency, which is expected in situations where the pulse generator is deprived of gonadal steroid feedback. This may be because endogenous GnRH pulses cannot trigger a rise in LH caused by the receptor impairment. These data demonstrate a wide spectrum of phenotypes and a great variation in the LH secretory pattern in isolated hypogonadotropic hypogonadism because of mutations in the GnRHR gene. This variable phenotype is obviously related to the allelic combination of the mutations in our kindred. The presence of the transmembrane domain mutation (A129D), associated with the R262Q mutation, is certainly responsible for the remarkable phenotype of this family. There is also a substantial variation in the degree of hypogonadotropic hypogonadism in patients with the same mutations in the GnRHR gene, because the endogenous LH secretions of the two brothers and their sister were different. This suggests that other factors influence the expression of the phenotype in such patients. Further studies on more patients are now required to address this issue.
Mutations in the receptors for hypothalamic hormones (TRH, GHRH) can
lead to complete resistance (19, 23, 24); missense mutations in the
GnRHR gene are analogous to those in the FSH or TSH receptor genes that
cause variable resistance to these hormones (25, 26, 27, 28, 29). Other patients
with mutations in their GnRHR gene (6, 7), like our siblings, had
increased gonadotropin concentrations after a phamacological GnRH test.
To assess the functionality of the mutated receptor, we have
administered iv pulsatile GnRH to the three siblings. An iv injection
of 25 ng/kg GnRH replicates normal gonadotropin secretion and causes
spermatogenesis or ovulation in most patients with idiopathic
hypogonadotropic hypogonadism (30, 31, 32). Pulses of GnRH (up to 115
ng/kg·pulse) in patients with spontaneous LH pulse of low amplitude,
increase mean circulating LH levels; and there was a significant change
in mean peak amplitude in patient II2. The half-life of immunoreactive
LH was shorter (but remained longer) than the value for the
normotestosteronemic father. In hypogonadic patients, we might
speculate that increased half-lives of immunoreactive LH resulted from
altered glycosylation of LH isoforms. Plasma testosterone
concentrations did not increase; they remained in the prepubertal
range, suggesting the persistent secretion of LH with low biological
activity (33). Finally, baseline and GnRH-stimulated inhibin B levels
varied in the two brothers, as reported for GnRH-deficient men before
and after short-term physiologic GnRH replacement (34). The small
effect of pulsatile GnRH on LH secretion in these patients may
therefore be caused by several factors. The interval between the
exogenous GnRH pulses might not have overridden the endogenous GnRH
activity. The pulsatile GnRH may have been given for too short a time
to induce complete gonadotropin and steroid responses, but a
significant increase in testosterone levels has been observed in men
with Kallmann syndrome after 2 or 3 days of physiologic GnRH
replacement (4, 30); or there may have been some degree of resistance
to GnRH in these patients. Patient II3, without any spontaneous LH
pulses, had an LH secretory profile that remained apulsatile throughout
the 40 h of exogenous GnRH administration at 133 ng/kg·pulse,
whereas each exogenous 265-ng/kg pulse of GnRH given for 24 h
triggered small LH pulses, demonstrating that her LH secretion did
respond to the exogenous GnRH. This patient produced an early increase
in free -subunit levels, within 3 days of the beginning of pulsatile
GnRH administration, whereas her LH secretory profile showed no
apparent LH pulse, suggesting that free -subunit secretion is
potentially a more sensitive index of GnRH action in hypogonadic
patients with mutated GnRHR gene. Similar data have been reported in
women with idiopathic hypogonadotropic hypogonadism, caused by
congenital GnRH deficiency, who respond to pulsatile GnRH treatment
(35). Our in vivo results thus demonstrate incomplete
resistance to GnRH in these hypogonadic patients with mutations of
GnRHR gene.
In conclusion, we have described a new kindred of three siblings, with isolated hypogonadotropic hypogonadism and compound heterozygote mutations in the GnRHR gene. Combined with previous reports, the phenotypic spectrum of such hypogonadism seems to vary, and this heterogeneity may be related, at least in part, to the degree of impaired biological activity of the mutated GnRHR caused by the allelic type of mutations. The transmembrane domain mutation (A129D), described here, may be responsible for the severity of this phenotype. The present study demonstrates incomplete resistance to pulsatile GnRH administration in these hypogonadic patients and suggests that they should be treated with gonadotropins to induce spermatogenesis (8) or ovulation (7), rather than with pulsatile GnRH treatment.
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Acknowledgments |
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-subunit kits. Received September 8, 1998.
Revised November 10, 1998.
Accepted November 16, 1998.
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References |
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TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
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I. L. Sedlmeyer, C. L. Pearce, J. A. Trueman, J. L. Butler, T. Bersaglieri, A. P. Read, P. E. Clayton, L. N. Kolonel, B. E. Henderson, J. N. Hirschhorn, et al. Determination of Sequence Variation and Haplotype Structure for the Gonadotropin-Releasing Hormone (GnRH) and GnRH Receptor Genes: Investigation of Role in Pubertal Timing J. Clin. Endocrinol. Metab., February 1, 2005; 90(2): 1091 - 1099. [Abstract] [Full Text] [PDF]
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A. U. Meysing, H. Kanasaki, G. Y. Bedecarrats, J. S. Acierno Jr., P. M. Conn, K. A. Martin, S. B. Seminara, J. E. Hall, W. F. Crowley Jr., and U. B. Kaiser GNRHR Mutations in a Woman with Idiopathic Hypogonadotropic Hypogonadism Highlight the Differential Sensitivity of Luteinizing Hormone and Follicle-Stimulating Hormone to Gonadotropin-Releasing Hormone J. Clin. Endocrinol. Metab., July 1, 2004; 89(7): 3189 - 3198. [Abstract] [Full Text] [PDF]
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R. P. Millar, Z.-L. Lu, A. J. Pawson, C. A. Flanagan, K. Morgan, and S. R. Maudsley Gonadotropin-Releasing Hormone Receptors Endocr. Rev., April 1, 2004; 25(2): 235 - 275. [Abstract] [Full Text] [PDF]
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 A. Ulloa-Aguirre, J. A. Janovick, A. Leanos-Miranda, and P. M. Conn Misrouted cell surface GnRH receptors as a disease aetiology for congenital isolated hypogonadotrophic hypogonadism Hum. Reprod. Update, March 1, 2004; 10(2): 177 - 192. [Abstract] [Full Text] [PDF]
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S. P. Brothers, J. A. Janovick, and P. M. Conn Unexpected Effects of Epitope and Chimeric Tags on Gonadotropin-Releasing Hormone Receptors: Implications for Understanding the Molecular Etiology of Hypogonadotropic Hypogonadism J. Clin. Endocrinol. Metab., December 1, 2003; 88(12): 6107 - 6112. [Abstract] [Full Text] [PDF]
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A. Leanos-Miranda, A. Ulloa-Aguirre, T. H. Ji, J. A. Janovick, and P. M. Conn Dominant-Negative Action of Disease-Causing Gonadotropin-Releasing Hormone Receptor (GnRHR) Mutants: A Trait That Potentially Coevolved with Decreased Plasma Membrane Expression of GnRHR in Humans J. Clin. Endocrinol. Metab., July 1, 2003; 88(7): 3360 - 3367. [Abstract] [Full Text] [PDF]
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Y. Bo-Abbas, J. S. Acierno Jr., J. K. Shagoury, W. F. Crowley Jr., and S. B. Seminara Autosomal Recessive Idiopathic Hypogonadotropic Hypogonadism: Genetic Analysis Excludes Mutations in the Gonadotropin-Releasing Hormone (GnRH) and GnRH Receptor Genes J. Clin. Endocrinol. Metab., June 1, 2003; 88(6): 2730 - 2737. [Abstract] [Full Text] [PDF]
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B. Karges, W. Karges, M. Mine, L. Ludwig, R. Kuhne, E. Milgrom, and N. de Roux Mutation Ala171Thr Stabilizes the Gonadotropin-Releasing Hormone Receptor in Its Inactive Conformation, Causing Familial Hypogonadotropic Hypogonadism J. Clin. Endocrinol. Metab., April 1, 2003; 88(4): 1873 - 1879. [Abstract] [Full Text] [PDF]
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G. Y. Bedecarrats, K. D. Linher, and U. B. Kaiser Two Common Naturally Occurring Mutations in the Human Gonadotropin-Releasing Hormone (GnRH) Receptor Have Differential Effects on Gonadotropin Gene Expression and on GnRH-Mediated Signal Transduction J. Clin. Endocrinol. Metab., February 1, 2003; 88(2): 834 - 843. [Abstract] [Full Text] [PDF]
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 P. M. Conn, A. Leanos-Miranda, and J. A. Janovick Protein Origami: Therapeutic Rescue of Misfolded Gene Products Mol. Interv., September 1, 2002; 2(5): 308 - 316. [Abstract] [Full Text] [PDF]
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J. A. Janovick, G. Maya-Nunez, and P. M. Conn Rescue of Hypogonadotropic Hypogonadism-Causing and Manufactured GnRH Receptor Mutants by a Specific Protein-Folding Template: Misrouted Proteins as a Novel Disease Etiology and Therapeutic Target J. Clin. Endocrinol. Metab., July 1, 2002; 87(7): 3255 - 3262. [Abstract] [Full Text] [PDF]
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J. C. Achermann, G. Ozisik, J. J. Meeks, and J. L. Jameson Genetic Causes of Human Reproductive Disease J. Clin. Endocrinol. Metab., June 1, 2002; 87(6): 2447 - 2454. [Full Text] [PDF]
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