It is shown that the process of mutation in the CYP2 family of the superfam
ily of P450 cytochromes is species-specific (man, rat, and mouse). It is al
so shown that, within one species (rat), different families (CYP2 and CYP11
) have different mutation spectral indicating a high specificity of the mut
ation process for the families of cytochrome genes. A similar specificity w
as demonstrated for five families (CYP1, CYP2, CYP6, CYP7, CYP11) as compar
ed with globins and prions. The analysis of the evolutionary mutation patte
rn, and the pattern of pseudogenes and damaged alleles of the CYP21 family
(found in patients with congenital adrenal hyperplasia) does not confirm th
e widely accepted hypothesis that mutations arising in pseudogenes are tran
sduced to normal alleles of the CYP21 gene through gene conversion.