Endocrine Abstracts

Insulin-like factor 3 (INSL3) is a testis-specific, Leydig cell derived hormone, which we recently demonstrated to play a role in bone metabolism. Young men with mutations in the gene for the INSL3 receptor (Relaxin family peptide 2, RXFP2) are at risk of reduced bone mass and osteoporosis. Consistent with the human phenotype, bone analyses of Rxfp2−/− mice showed decreased bone volume, alterations of the trabecular bone, reduced mineralizing surface, bo...

Klinefelter syndrome (KS) was first described in 1942 and the cause for the syndrome was identified as a supernumerary X chromosome resulting in the karyotype 47,XXY. 80–90% of KS cases bear this karyotype, whereas the remaining exhibit (in decreasing frequency) varying mosaicism (e.g. 47,XXY/46,XY), carry additional sex chromosomes (48,XXXY; 48,XXYY; 49,XXXXY) or structurally abnormal X chromosomes. The prevalence of KS is up to 1 in 500 boys, and it is the most common c...