Genetic diagnosis of 21‐hydroxylase deficiency: DGGE‐based mutation scanning of CYP21

Congenital adrenal hyperplasia (CAH) due to 21‐hydroxylase deficiency is caused by mutations in the gene CYP21 encoding the enzyme steroid 21‐hydroxylase. In addition to deletions, approximately 20 different point mutations have been reported, and still novel mutations are detected. This makes genetic diagnosis as well as carrier detection of 21‐hydroxylase deficiency a complicated matter. We developed a simple nonradioactive assay based on the polymerase chain reaction (PCR) in combination with denaturing gradient gel electrophoresis (DGGE) to screen for mutations in the CYP21 gene. DGGE allows a fast scanning of PCR‐amplified segments of genes for the presence or absence of any single base pair alterations. We have performed this technique on the coding sequence and intron‐exon junctions of CYP21. Our results emphasize that this procedure constitutes a fast and reliable approach when performing diagnosis of 21‐hydroxylase deficiency. Hum Mutat 13:385–389, 1999. © 1999 Wiley‐Liss, Inc.