Rs6467

Note that this SNP is unusual in at least two regards. First, it is defined in both dbSNP and here in SNPedia (currently at least) as being on the minus strand, even though the vast majority of its fellow CYP21A2 gene SNPs are defined on the plus strand. The literature and most (other) databases define this SNP based on the plus strand.

Second, there are three alleles for this SNP; as defined on the minus strand, there are plenty of individuals walking around with rs6467(G) and rs6467(T) alleles, both of which lead to fully functional 21-hydroxylase (the enzyme encoded by the CYP21A2 gene), and there are also some individuals carrying a rs6467(C) allele, which severely reduces enzyme activity.

The rs6467(T) polymorphism defines the CYP21A2*1B allele according to the CYP21A2 Nomenclature table. The allele with impaired function, rs6467(C), is the CYP21A2*9 allele.

See further details at congenital adrenal hyperplasia.