Study on a pedigree with Leydig cell hypoplasia caused by novel mutation of luteinizing hormone receptor

Objective To investigate a Chinese pedigree suffering from Leydig cell hypoplasia ( LCH) based on clinical data and genetic diagnosis. Methods The patient was diagnosed by means of clinical data, hormone profiles, and human chorionic gonadotropin ( hCC) test. The luteinizing hormone/chorionic gonadotropin receptor(LHCGR) gene of the patient and family members was amplified and sequenced. Results The patient presented with male pseudohermaphroditism, low level of testosterone, which did not respond to hCG. Genetic analysis of the LHCGR revealed two novel mutations: a missense mutation located in exon 5, resulting in Ile replaced by Thr in the extracellular domain; and a splice site mutation in the 3' terminal of intron 6( IVS6-3 C→A). Proband's sister (46, XX) who lacked clinical manifestations showed the identical genotype with the patient. Conclusions A mutation in the consensus sequence of 3' splice site, in addition to a missense mutation (Ile 152Thr)in the extracellular ligand-binding domain is the cause of inactivation of the LHCGR gene in patient with Leydig cell hypoplasia. Key words: Luteinizing hormone/chorionic gonadotropin receptor;  Male pseudohermaphroditism;  Leydig cell hypoplasia