title: 5 alpha-reductase deficiency: diagnosis via abnormal plasma levels of reduced testosterone derivatives.
abstract: A case of 5 alpha-reductase deficiency is described who presented clinically as primary amenorrhoea. Plasma levels of the two isomers resulting from the 5 alpha-reduction of testosterone provide a simple method for diagnosing this condition. An intermediate abnormality was found in other family members consistent with the heterozygous state.
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000172:deficiency*; D000328:Adult; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D013196:Dihydrotestosterone / Q000097:blood; D012734:Disorders of Sex Development / Q000175:diagnosis / Q000201:enzymology* / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D010088:Oxidoreductases / Q000172:deficiency*; D013737:Testis / Q000473:pathology; D013739:Testosterone / Q000097:blood*
chemical_list: D006063:Chorionic Gonadotropin; D013196:Dihydrotestosterone; D013739:Testosterone; D010088:Oxidoreductases; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase