Multiplex ligation-dependent probe amplification assay for diagnosis of congenital adrenal hyperplasia.

Mutations in the CYP21A2 gene encoding the 21-hydroxylase enzyme account for >90% of congenital adrenal hyperplasia (CAH) cases. Approximately 20% of mutant alleles carrying large deletion/duplication have also been reported. Herein, we describe the use of the multiplex ligation-dependent probe amplification (MLPA) method for convenient and rapid detection of deletions/duplications in the CYP21A2 gene. We used MLPA to analyze the gene dose of CYP21A2 MLPA in 13 Korean patients who previously underwent direct sequencing for the molecular diagnosis of CAH. The MLPA assays identified 5 patients with CYP21A2 deletions; all 5 patients carried a single mutant allele peak in sequence analysis. These results demonstrate the diagnostic usefulness of MLPA to detect CYP21A2 deletions/duplications for diagnosis of CAH.