5-alpha Reductase - Isoenzymes

Isoenzymes

There are three isoenzymes, steroid 5α-reductase 1,2 and 3 (SRD5A1, SRD5A2 and SRD5A3).

The second isoenzyme is deficient in 5α-reductase deficiency, which leads to a form of intersexualism.

Type III is also required for the glycosylation, it converts polyprenol to dolichol. The gen (SRD5A3) is mutated in a form of the congenital glycosylation disorder (CDGs).