Genetic analysis of two Japanese patients with non-classical 21-hydroxylase deficiency.

We report two Japanese women with androgen excess symptoms. Analyses of 21-hydroxylase gene demonstrated that a 24-year-old Japanese woman had a homozygous mutation of IVS2-13 A/C>G, while a 25-year-old Japanese woman had a compound heterozygous mutation of I172N and E245del1nt, a novel mutation which would result in completely nonfunctional enzyme due to a frame shift. As IVS2-13 A/C>G and I172N have been classified as mutations leading to severe impairment in enzyme activity, this study not only clarified a novel mutation causing 21-hydroxylase deficiency, but also demonstrated that genotype and phenotype do not correlate well in these cases.