Objective: To investigate the molecular defects of CYP17A1 gene in a pedigree with two 46,XY patients suffering from 17alpha-hydroxylase deficiency (17-OHD) and explore the steroid biosynthetic difference in carriers of 17-OHD before and after adrenocorticotrophic hormone (ACTH) test.
Methods: Clinical data and hormone profiles were collected from the members of the pedigree. CYP17A1 genotyping was performed in the patients and family members with PCR-direct sequencing. A short ACTH test was evaluated in some cases.
Results: The CYP17 genes of the patients were proved to hold a homozygous mutation with a base deletion and a base transversion (TAC/AA) in exon 6, which produced a missense mutation of Tyr-->Lys at codon 329 and changed the open reading frame following this codon. The hormone response of the carriers after ACTH stimulation was abnormal between the patients and normal controls.
Conclusion: 17-OHD in this family was caused by CYP17A1 mutation (TAC329AA); some hormonal response to ACTH stimulation was abnormal in carriers.