115 Detection of heterozygous carrier for 21-hydroxylase deficiency by plasma 21-deoxycortisol measurment

Abstract

Plasma 21-deoxycortisol (21 DF) was measured by using an anti-serum raised in the rabbit with 21-deoxycortisol-3-0-carboxymethyl oxime-BSA. This anti-serum cross-reacted with 11-deoxycortisol (0.08%), corticosterone (0.35%), cortisol (0.6%) and 17-hydroxyprogesterone (1.6%). 21 DF was separated by celite partition chromatography and was eluted in the fraction isooctane 70v/ethylacetate 30v, together with 11-deoxycortisol and corticosterone. In 38 healthy volunteers (16 men and 22 women) 21 DF mean basal value was 166 pg/ml at 8 a.m. with a range of 66 - 401 pg/ml. After a Synacthen test, performed in 14 subjects, the maximum mean level was 414 pg/ml (151-930). In 31 congenital adrenal hyperplasia family members heterozygous for 21-hydroxylase deficiency proved by HLA genotyping, 21 DF mean basal level was 323 pg/ml (50-1,380). After Synacthen it increased up to 2,380 (1,070-9,060). In contrast with 17-hydroxyprogesterone which was also measured and which remained in the normal range after Synacthen in 12 cases out of the 31 , 21 DF under stimulation increased to pathological levels in all the cases studied. Therefore we believe that plasma 21 DF measurement could be of great interest in the biological detection of heterezygous subjects for 21-hydroxylase deficiency.