title: Ascertainment of 21-hydroxylase deficiency in individuals with HLA-B14 haplotype.
abstract: 21-Hydroxylase activity was measured in North American caucasian individuals with the HLA-B14 antigen to estimate the frequency of heterozygosity for the attenuated congenital adrenal hyperplasia trait. A 30-min iv ACTH stimulation test was administered to 9 normal HLA-B14-positive subjects and to a comparable HLA-B14-negative control group. Changes in plasma progesterone and 17-hydroxyprogesterone over 30 min were summed and expressed as a combined rate of rise. Six of 9 HLA-B14-positive individuals had a rate of rise greater than 2 SD above the mean control value. On this basis, about two thirds of B-14-positive individuals are heterozygote carriers for 21-hydroxylase deficiency. Thus, the frequency of the attenuated form of congenital adrenal hyperplasia linked to the HLA-B14 locus in women is approximately 1 in 6000 if there is only 1 B14, and 1 in 2000 if there are 2 B14s in the HLA type.
mesh_terms: D019326:17-alpha-Hydroxyprogesterone; D000312:Adrenal Hyperplasia, Congenital / Q000175:diagnosis / Q000201:enzymology / Q000235:genetics*; D000328:Adult; D003366:Cosyntropin; D005260:Female; D006680:HLA Antigens / Q000235:genetics*; D015235:HLA-B Antigens; D059909:HLA-B14 Antigen; D006238:Haploidy; D006579:Heterozygote; D006801:Humans; D006908:Hydroxyprogesterones / Q000097:blood; D008297:Male; D008875:Middle Aged; D011374:Progesterone / Q000097:blood; D013250:Steroid Hydroxylases / Q000172:deficiency*
chemical_list: D006680:HLA Antigens; D015235:HLA-B Antigens; D059909:HLA-B14 Antigen; D006908:Hydroxyprogesterones; D003366:Cosyntropin; D011374:Progesterone; D019326:17-alpha-Hydroxyprogesterone; D013250:Steroid Hydroxylases