Cytochrome P450 family 21 subfamily A member 1, pseudogene (CYP21A1P)

Cytochrome P450 family 21 subfamily A member 1, pseudogene (CYP21A1P) is a *non-functional pseudogene* located in the major histocompatibility complex (MHC) class III region on chromosome 6. It arose as a duplicated copy of the functional CYP21A2 gene but contains multiple mutations (including point mutations, frame shifts, and deletions) that prevent it from encoding a functional 21-hydroxylase enzyme. Although CYP21A1P is transcribed, its mRNA does not result in a functional protein. The high sequence similarity between CYP21A1P and CYP21A2 makes molecular analysis of the functional gene challenging and allows for intergenic recombination events, which can cause pathogenic variants in CYP21A2 underlying most cases of congenital adrenal hyperplasia (CAH)[2][3][4][5][6][7][8]. CYP21A1P is not itself a therapeutic target, enzyme, or receptor, but its presence and sequence can indirectly affect disease through genetic recombination mechanisms; thus, it is classified as a pseudogene and is not directly implicated in therapeutic strategies.

Other names

P450c21ACytochrome P450, Subfamily XXIA (Steroid 21-hydroxylase), Polypeptide 1 pseudogeneCytochrome P450, Family 21, Subfamily A, Polypeptide 1 pseudogeneCYP21ACYP21PCytochrome P450, Subfamily XXI (Steroid 21-hydroxylase) pseudogene