Endocrine Abstracts

The GNAS locus (chromosome 20q13) yields multiple transcripts, including the stimulatory G protein subunit α (Gsα), NESP55, GsαXL and two noncoding RNAs, the GNAS1A-transcript (A/B) and the antisense transcript (AS). The corresponding promoters show a complex methylation pattern resulting in an allele-specific imprinting, with maternal expression of NESP55 and paternal expression of GNAS1A, GsαXL and AS. Gsα in most tissues is derived from both alleles...

Hypophosphatemic rickets is an X-linked dominant inherited bone disorder, characterized by renal phosphate wasting, inappropriately normal to low vitamin D serum levels and severe skeletal and dental defects from early childhood. Inactivating mutations in the PHEX gene (phosphate regulating gene with homologies to endopeptidases on the X-chromosome) have been identified as the underlying cause, although the pathomechanism is unknown. The PHEX gene encodes a membrane-bound meta...

Two dominant inherited disorders of phosphate homeostasis, X-linked hypophosphatemia (XLH), and ADHR are known to be caused by inactivating mutations in the PHEX gene or activating mutations in the FGF23 gene (fibroblast growth factor 23), respectively. Both diseases show a similar phenotype with renal phosphate wasting and inappropriately normal or low 1,25-(OH)2-Vitamin D3 serum levels, leading to hypophosphatemic rickets and osteomalacia. The different...