DNA and RNA analysis of cytochrome P-450 21-hydroxylase: transcriptional activity in congenital adrenal hyperplasia.
Congenital adrenal hyperplasia (CAH) is a family of inherited disorders of adrenal steroidogenesis, most commonly due to deficiency of P-450 21-hydroxylase (21-OH). There are two genes for 21-OH on the short arm of chromosome 6, the A gene which is thought to be inactive, and the B gene. These genes appear as 3.2 and 3.7 kb TaqI fragments on Southern blots. In a study of DNA from 60 normal controls with TaqI and a 21-OH cDNA probe, 12% exhibited a homozygous deletion of the A gene, and 22 and 8% heterozygous deletions of A and B genes respectively. TaqI analysis of eight patients with CAH revealed four without A or B gene deletions, three with heterozygous deletions of the B gene and one with a homozygous deletion of the B gene. On further analysis with KpnI, EcoRI, PvuII and BglII, however, these genotypes were amended to two with heterozygous deletions of the B gene and two with possible B to A gene conversions. The genotypes of the four patients without deletions remained unchanged. RNA from CAH and Cushing's adrenal tissue was also analysed using A and B gene-specific oligodeoxynucleotide probes. B gene transcripts were detected in both CAH and Cushing's adrenals, while no A gene transcripts could be detected in either tissue. The level of B gene-derived mRNA was greater in the Cushing's adrenal than in the CAH adrenal, which in turn was greater than that in the adrenal from a normal individual.(ABSTRACT TRUNCATED AT 250 WORDS)
al-Othman
A N
AN
Department of Medicine, University of Birmingham, Queen Elizabeth Hospital, London.
Docherty
K
K
Makgoba
M W
MW
Sheppard
M C
MC
London
D R
DR
D000311:Adrenal Glands / Q000032:analysis; D000312:Adrenal Hyperplasia, Congenital / Q000235:genetics*; D015152:Blotting, Northern; D015139:Blotting, Southern; D002872:Chromosome Deletion; D003480:Cushing Syndrome / Q000235:genetics*; D015252:Deoxyribonucleases, Type II Site-Specific; D006680:HLA Antigens / Q000235:genetics; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D012313:RNA / Q000032:analysis; D013255:Steroid 21-Hydroxylase / Q000235:genetics*; D013250:Steroid Hydroxylases / Q000235:genetics*
D006680:HLA Antigens; D012313:RNA; D013250:Steroid Hydroxylases; D013255:Steroid 21-Hydroxylase; D015252:Deoxyribonucleases, Type II Site-Specific; C027046:TCGA-specific type II deoxyribonucleases