Molecular genetic study of acute intermittent porphyria in Russia: HMBS gene mutation spectrum and problem of penetrance.

Acute intermittent porphyria (AIP) is the most common and severe form of porphyrias. This is a dominant inherited disorder with low penetrance, caused by mutations in gene coding hydroxymethylbilane synthase (HMBS). We present the results of our long-term genetic study of AIP patients and their relatives (N = 153 and 302, respectively).