Location of the gene for 21-hydroxylase deficiency.

HLA typing of 33 families with one or more children suffering from congenital adrenal hyperplasia confirmed that the gene for 21-hydroxylase deficiency is closely associated with the HLA region. Analysis of two families in which recombination of chromosome 6 had occurred indicated that the gene locus is between the A and D loci of the HLA region. The rare allele Bw47 was observed in 18 parents and was always associated with the carrier state for 21-hydroxylase deficiency.