Application of polymerase chain reaction with oligoligation assay to determine genotype in individuals presenting with congenital adrenal hyperplasia

Abstract

Background: Current methods for the molecular diagnosis of the 21-hydroxylase deficiency variant of congenital adrenal hyperplasia use cumbersome combinations of Southern blotting and polymerase chain reaction (PCR). The aim of the present study was to develop a practical genetic test for the unambiguous diagnosis of this condition, and to use this procedure to determine the range of mutations in Scottish patients. In addition, we wished to obtain further information to that currently available in the literature regarding the correlation of genotype with phenotype in any identified carriers. Methods: We studied five Scottish probands and their family members. To try to obviate the need for Southern blotting, we investigated a technique that uses the oligoligation chain reaction after gene-specific PCR. Results: We found a spectrum of mutations in the ten unrelated mutant alleles studied. These consisted of at least three different 30-kb deletions, two intron 2 splice-site mutations and single occurrences of the 1172N, V281L and R356W substitutions. Conclusions: The genotype-phenotype correlations agreed with those previously described. In addition, our results suggest that there is no predominant Scottish genotype.