A de novo pathological point mutation at the 21-hydroxylase locus: implications for gene conversion in the human genome.
More than two hundred characterized 21-hydroxylase deficiency alleles appear to result exclusively from sequence exchanges involving the 21-hydroxylase gene (CYP21B) and a closely related pseudogene (CYP21A). Gene conversion-like events have also been reported in many other human gene clusters, but in the absence of a de novo mutation, the alternative explanation of a multiple recombination is possible. We now report a de novo pathological mutation at the 21-hydroxylase locus. DNA sequence analysis suggests that the mutation arose by a microconversion event involving exchange of up to 390 nucleotides between maternal CYP21A and CYP21B genes. This putative de novo gene conversion event appears to be the first characterized in humans.
Collier
S
S
University Department of Medical Genetics, St. Mary's Hospital, Manchester, UK.
Tassabehji
M
M
Sinnott
P
P
Strachan
T
T
D000312:Adrenal Hyperplasia, Congenital; D000483:Alleles; D001483:Base Sequence; D005260:Female; D005785:Gene Conversion; D005819:Genetic Markers; D015894:Genome, Human; D006680:HLA Antigens / Q000235:genetics; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family; D010375:Pedigree; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011544:Pseudogenes; D011995:Recombination, Genetic; D017384:Sequence Deletion; D012689:Sequence Homology, Nucleic Acid; D013255:Steroid 21-Hydroxylase / Q000235:genetics*; D014770:Virilism / Q000201:enzymology / Q000235:genetics
D005819:Genetic Markers; D006680:HLA Antigens; D013255:Steroid 21-Hydroxylase