| 9685133 | R31C GNRH1 mutation and congenital hypogonadotropic hypogonadism. | Maione L, etal., PLoS One. 2013 Jul 25;8(7):e69616. doi: 10.1371/journal.pone.0069616. Print 2013. | Normosmic congenital hypogonadotropic hypogonadism (nCHH) is a rare reproductive disease leading to lack of puberty and infertility. Loss-of-function mutations of GNRH1 gene are a very rare cause of autosomal recessive nCHH. R31C GNRH1 GNRH1 is the only missense mutation that affects the conserved GnRH decapeptide sequence. This mutation was identified in a CpG islet in nine nCHH subjects from four unrelated families, giving evidence for a putative "hot spot". Interestingly, all the nCHH patients carry this mutation in heterozygosis that strikingly contrasts with the recessive inheritance associated with frame shift and non-sense mutations. Therefore, after exclusion of a second genetic event, a comprehensive functional characterization of the mutant R31C GnRH was undertaken. Using different cellular models, we clearly demonstrate a dramatic reduction of the mutant decapeptide capacity to bind GnRH-receptor, to activate MAPK pathway and to trigger inositol phosphate accumulation and intracellular calcium mobilization. In addition it is less able than wild type to induce lh-beta transcription and LH secretion in gonadotrope cells. Finally, the absence of a negative dominance in vitro offers a unique opportunity to discuss the complex in vivo patho-physiology of this form of nCHH. | 23936060 | 1000-12-01 |
| 9685134 | Isolated familial hypogonadotropic hypogonadism and a GNRH1 mutation. | Bouligand J, etal., N Engl J Med. 2009 Jun 25;360(26):2742-8. doi: 10.1056/NEJMoa0900136. Epub 2009 Jun 17. | We investigated whether mutations in the gene encoding gonadotropin-releasing hormone 1 (GNRH1) might be responsible for idiopathic hypogonadotropic hypogonadism (IHH) in humans. We identified a homozygous GNRH1 frameshift m utation, an insertion of an adenine at nucleotide position 18 (c.18-19insA), in the sequence encoding the N-terminal region of the signal peptide-containing protein precursor of gonadotropin-releasing hormone (prepro-GnRH) in a teenage brother and sister, who had normosmic IHH. Their unaffected parents and a sibling who was tested were heterozygous. This mutation results in an aberrant peptide lacking the conserved GnRH decapeptide sequence, as shown by the absence of immunoreactive GnRH when expressed in vitro. This isolated autosomal recessive GnRH deficiency, reversed by pulsatile GnRH administration, shows the pivotal role of GnRH in human reproduction. | 19535795 | 2009-12-01 |
| 9685137 | GNRH1 mutations in patients with idiopathic hypogonadotropic hypogonadism. | Chan YM, etal., Proc Natl Acad Sci U S A. 2009 Jul 14;106(28):11703-8. doi: 10.1073/pnas.0903449106. Epub 2009 Jun 30. | Idiopathic hypogonadotropic hypogonadism (IHH) is a condition characterized by failure to undergo puberty in the setting of low sex steroids and low gonadotropins. IHH is due to abnormal secretion or action of the master reproductive hormone gonadotropin-releasing hormone (GnRH). Several genes have been found to be mutated in patients with IHH, yet to date no mutations have been identified in the most obvious candidate gene, GNRH1 itself, which encodes the preprohormone that is ultimately processed to produce GnRH. We screened DNA from 310 patients with normosmic IHH (nIHH) and 192 healthy control subjects for sequence changes in GNRH1. In 1 patient with severe congenital nIHH (with micropenis, bilateral cryptorchidism, and absent puberty), a homozygous frameshift mutation that is predicted to disrupt the 3 C-terminal amino acids of the GnRH decapeptide and to produce a premature stop codon was identified. Heterozygous variants not seen in controls were identified in 4 patients with nIHH: 1 nonsynonymous missense mutation in the eighth amino acid of the GnRH decapeptide, 1 nonsense mutation that causes premature termination within the GnRH-associated peptide (GAP), which lies C-terminal to the GnRH decapeptide within the GnRH precursor, and 2 sequence variants that cause nonsynonymous amino-acid substitutions in the signal peptide and in GnRH-associated peptide. Our results establish mutations in GNRH1 as a genetic cause of nIHH. | 19567835 | 2009-12-01 |
| 11561198 | Complete Idiopathic Hypogonadotropic Hypogonadism due to Homozygous GNRH1 Mutations in the Mutational Hot Spots in the Region Encoding the Decapeptide. | Mengen E, etal., Horm Res Paediatr. 2016;85(2):107-11. doi: 10.1159/000441977. Epub 2015 Nov 24. | INTRODUCTION: Mutations of the human GNRH1 gene are an extremely rare cause of normosmic idiopathic hypogonadotropic hypogonadism (nIHH), with only 6 mutations so far described. PATIENTS: As part of a larger study, families with IHH were screened for mutations in genes known to be associated with IHH. In family 1, a 15-year and 9-month-old boy first presented during infancy with micropenis and bilateral cryptorchidism. His pubic and axillary hair is at stage 4 and 2, respectively. His testes are 1 ml bilaterally, and his stretched penile length is 3.6 cm. In family 2, a 19-year and 2-month-old man was referred because of absence of secondary sexual characteristics. His 13-year and 8-month-old sister did not have any breast development. RESULTS: In 3 patients from 2 independent families we identified GNRH1 mutations. In the proband from family 1, a homozygous 1-base deletion (c.87delA) leading to a frameshift mutation (p.G29GfsX12) was identified. In family 2, the affected siblings had a novel homozygous mutation of c.G92A leading to p.R31H. CONCLUSION: Both mutations in these families are located in the region encoding the decapeptide and in the loci where the mutations have been described before. Therefore, these areas can be considered as mutational hot spots, indicating priority for routine diagnostic gene mutation analysis. | 26595427 | 1000-11-01 |
