Decreased 3α-androstanediol glucuronide levels in plasma and random urines in male pseudohermaphroditism caused by 5α-reductase deficiency

Concentrations of 3α-diol glucuronide (3α-diol G) in plasma and/or random urine samples were determined in seven subjects with familial male pseudohermaphroditism (FMP) due to 5α-reductase deficiency (5α-RD). All subjects were natives of an isolated Turkish village with a high incidence of consanguineous marriage. A specific and sensitive antibody to 3α-diol was used for radioimmunassay of 3α-diol G after hydrolysis and chromatographic purification. The mean plasma 3α-diol G in three subjects (31 ng/dL) was much lower than the normal male concentration (516 ± 50) (± SE) and was even lower than normal female values (119 ± 10.9 ng/dL). In five subjects, mean urinary 3α-diol G in random urine samples was 7.6 (range 2.1 to 12.7) ng/mg creatinine. This was considerably decreased compared with the mean adult male concentration of 65.4 ± 9.4 and even lower than normal age-matched nonhirsute female values (19.6 ± 2.1 ng/mg Cr). To validate the use of 3α-diol G/creatinine ratios in random urine samples, correlations of three consecutive eight-hour samples with 24-hour values were determined in 8 male and 3 female age-matched controls. There was an excellent correlation ( r = .95) and the linear regression line (y = 0.51 x + 2.58) indicates that the 24-hour excretion of 3α-diol G in μg/24 h is approximately twice the random urinary concentration in ng/mg Cr. In patients with FMP due to 5α-RD, (1) plasma and urinary 3α-diol G values are markedly decreased compared with those seen in normal males, (2) 3α-diol G/creatinine ratios in random urines can be used when a 24-hour collection is not feasible, and (3) the strong correlation of these decreased values with the decreased sexual hair and sebum production in these subjects expands the usefulness of this assay in assessing peripheral androgen activity.