title: The prevalence of 5 alpha-reductase deficiency in children with ambiguous genitalia in the Dominican Republic.
abstract: During a 10-year period 65 children and adolescents with ambiguous genitalia from the Dominican Republic, not known through kindred studies of 5 alpha-reductase deficiency, were evaluated. Plasma androgen determinations were performed before and/or after Leydig cell stimulation of the testes with human chorionic gonadotropin. Of the children there were 24 female pseudohermaphrodites, 21 of whom had 21-hydroxylase deficiency, 1 true hermaphrodite and 40 (62 per cent) male pseudohermaphrodites. One child had a human chorionic gonadotropin response suggestive of 17-20 desmolase deficiency, and on further evaluation he also had partial deficiencies of the enzymes 21-hydroxylase and 17 alpha-hydroxylase. Five subjects had a female phenotype and subnormal androgen responses to human chorionic gonadotropin. In 5 of 33 male pseudohermaphrodites with a normal testosterone response to human chorionic gonadotropin 5 alpha-reductase deficiency was suspected by elevated plasma testosterone/dihydrotestosterone ratios before and/or after human chorionic gonadotropin stimulation. The diagnosis of 5 alpha-reductase deficiency was confirmed by elevated 5 beta/5 alpha urinary C19 and C21 steroid metabolite ratios. One subject with 5 alpha-reductase deficiency was traced to the original Dominican kindred of 38 affected subjects. Pedigree analysis of another proband revealed 3 additional affected relatives. Four subjects with a normal testosterone response to human chorionic gonadotropin had XO/XY gonadal dysgenesis. There were 25 male pseudohermaphrodites with normal plasma testosterone and dihydrotestosterone responses to human chorionic gonadotropin, who were not diagnosed by this methodology. This study reveals that 5 alpha-reductase deficiency occurs with a frequency of 13 per cent as a cause of male pseudohermaphroditism in the Dominican Republic with approximately the same frequency as XO/XY gonadal dysgenesis. Unlike female pseudohermaphrodites, the majority of male subjects with pseudohermaphroditism remain unclassified by these techniques.
mesh_terms: D000293:Adolescent; D000312:Adrenal Hyperplasia, Congenital; D002648:Child; D042944:Cholestenone 5 alpha-Reductase; D012734:Disorders of Sex Development / Q000201:enzymology* / Q000235:genetics; D004293:Dominican Republic; D005260:Female; D005838:Genotype; D006059:Gonadal Dysgenesis / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D008297:Male; D010088:Oxidoreductases / Q000172:deficiency*; D010375:Pedigree; D013739:Testosterone / Q000097:blood
chemical_list: D013739:Testosterone; D010088:Oxidoreductases; D042944:Cholestenone 5 alpha-Reductase