A NEW VARIANT OF THE CYTOCHROME-P450C17(CYP17) GENE MUTATION IN 3 PATIENTS WITH 17-ALPHA-HYDROXYLASE DEFICIENCY

A new CYP17 gene abnormality was found in three Japanese patients with 17 alpha-hydroxylase deficiency (17OHD). These patients were children from consanguineous marriages, but from two apparently unrelated fami lies: one patient with 46, XY karyotype, and two siblings with 46, XX and 46: XY karyotypes. They were all raised as girls and presented wit h amenorrhea, eunuchoid appearance and hypertension. Gene analysis rev ealed two base-pair (TG) deletion in exon 5 (codons 300? 301) of the C YP17 gene. This deletion could be expected to alter the reading frame resulting in the lack of a haem-binding region (Cys 442) due to a prem ature stop codon at position 333. This small mutation may account for the patients' clinical manifestations of 17OHD.