33 research outputs found
POU6F2 mutation in humans with pubertal failure alters GnRH transcript expression
Idiopathic hypogonadotropic hypogonadism (IHH) is characterized by the absence of pubertal development and subsequent impaired fertility often due to gonadotropin-releasing hormone (GnRH) deficits. Exome sequencing of two independent cohorts of IHH patients identified 12 rare missense variants in POU6F2 in 15 patients. POU6F2 encodes two distinct isoforms. In the adult mouse, expression of both isoform1 and isoform2 was detected in the brain, pituitary, and gonads. However, only isoform1 was detected in mouse primary GnRH cells and three immortalized GnRH cell lines, two mouse and one human. To date, the function of isoform2 has been verified as a transcription factor, while the function of isoform1 has been unknown. In the present report, bioinformatics and cell assays on a human-derived GnRH cell line reveal a novel function for isoform1, demonstrating it can act as a transcriptional regulator, decreasing GNRH1 expression. In addition, the impact of the two most prevalent POU6F2 variants, identified in five IHH patients, that were located at/or close to the DNA-binding domain was examined. Notably, one of these mutations prevented the repression of GnRH transcripts by isoform1. Normally, GnRH transcription increases as GnRH cells mature as they near migrate into the brain. Augmentation earlier during development can disrupt normal GnRH cell migration, consistent with some POU6F2 variants contributing to the IHH pathogenesis
Inactivating KISS1 mutation and hypogonadotropic hypogonadism
Gonadotropin-releasing hormone (GnRH) is the central regulator of gonadotropins,
which stimulate gonadal function. Hypothalamic neurons that produce kisspeptin
and neurokinin B stimulate GnRH release. Inactivating mutations in the genes encoding
the human kisspeptin receptor (KISS1R, formerly called GPR54), neurokinin
B (TAC3), and the neurokinin B receptor (TACR3) result in pubertal failure. However,
human kisspeptin loss-of-function mutations have not been described, and contradictory
findings have been reported in Kiss1-knockout mice. We describe an inactivating
mutation in KISS1 in a large consanguineous family that results in failure of
pubertal progression, indicating that functional kisspeptin is important for puberty
and reproduction in humans. (Funded by the Scientific and Technological Research
Council of Turkey [TÜBİTAK] and others.)http://www.nejm.org/nf201
Wolcott-Rallison Syndrome
Wolcott-Rallison syndrome (WRS) is a rare autosomal-recessive disorder characterized by the association of permanent neonatal or early-infancy insulin-dependent diabetes, multiple epiphyseal dysplasia and growth retardation, and other variable multisystemic clinical manifestations. Based on genetic studies of two inbred families, we previously identified the gene responsible for this disorder as EIF2AK3, the pancreatic eukaryotic initiation factor 2α (eIF2α) kinase. Here, we have studied 12 families with WRS, totalling 18 cases. With the exception of one case, all patients carried EIF2AK3 mutations resulting in truncated or missense versions of the protein. Exclusion of EIF2AK3 mutations in the one patient case was confirmed by both linkage and sequence data. The activities of missense versions of EIF2AK3 were characterized in vivo and in vitro and found to have a complete lack of activity in four mutant proteins and residual kinase activity in one. Remarkably, the onset of diabetes was relatively late (30 months) in the patient expressing the partially defective EIF2AK3 mutant and in the patient with no EIF2AK3 involvement (18 months) compared with other patients (<6 months). The patient with no EIF2AK3 involvement did not have any of the other variable clinical manifestations associated with WRS, which supports the idea that the genetic heterogeneity between this variant form of WRS and EIF2AK3 WRS correlates with some clinical heterogeneity
Extremely immature infant who developed clitoromegaly during the second month of her postnatal life probably due to frequent whole blood transfusion from an adult male
PubMedID: 12828595[No abstract available
A NOVEL FRAMESHIFT MUTATION IN ESCO2 GENE CAUSE ROBERTS SYNDROME: CASE PRESENTATION
WOS: 000412595404145
CHILDHOOD METASTATIC ADRENOCORTICAL CARCINOMA: CASE PRESENTATION
WOS: 000412595405014
COMBINATION OF HIRSCHSPRUNG DISEASE AND A NOVEL DEFINED MUTATION RELATED CONGENITAL ADRENAL HYPERPLASIA IN CYP21A2 GENE: CASE PRESENTATION
WOS: 000412595405015
A CASE OF SEX DEVELOPMENT DISORDER DUE TO A NOVEL MUTATION IN 5 ALFA REDUCTASE (SRD5A2) GENE
WOS: 000412595404122