title: Classical and late-onset forms of congenital adrenal hyperplasia caused by 21-OH deficiency reveal different alterations in the C4/21-OH gene region.
abstract: Congenital adrenal hyperplasia (CAH) is due to defective adrenal cortisol biosynthesis. In most cases, deficiency of a P 450-C21 specific steroid hydroxylase impairing cortisol synthesis has been found. The disease is HLA-linked, and on clinical grounds it can be divided into two major forms, the classical and the non-classical type. Here, evidence is presented that the classical and the non-classical forms of CAH caused by 21-OH deficiency are due to different genetic alterations in the C4/21-OH gene region. In most cases of classical CAH associated with the HLA-Bw47 antigen, a specific and selective loss of the 21-OH B gene was observed with some interesting exceptions. Alterations in the 21-OH gene region in the non-classical forms of CAH, patients either HLA-B14; DR1 homo- or heterozygous, are different. Our data indicate the possibility of gene conversion events in this genomic region in non-classical CAH.
mesh_terms: D000312:Adrenal Hyperplasia, Congenital / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D000367:Age Factors; D003181:Complement C4 / Q000235:genetics*; D004262:DNA Restriction Enzymes; D006680:HLA Antigens / Q000235:genetics; D006239:Haplotypes; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D013255:Steroid 21-Hydroxylase / Q000235:genetics*; D013250:Steroid Hydroxylases / Q000235:genetics*
chemical_list: D003181:Complement C4; D006680:HLA Antigens; D013250:Steroid Hydroxylases; D013255:Steroid 21-Hydroxylase; D004262:DNA Restriction Enzymes