High Frequency of the R117H Cystic Fibrosis Mutation in Patients with Congenital Absence of the Vas Deferens

Abstract
We have previously described an increased frequency of the δF508 mutation of the cystic fibrosis gene in a group of patients with congenital absence of the vas deferens1. This suggested that patients heterozygous for the δF508 mutation may have a mutation on another allele. We have looked for other mutations of the cystic fibrosis gene in a group of 23 patients with congenital absence of the vas deferens, 11 of whom were heterozygous for the δF508 mutation. We found that four patients were compound heterozygotes, all having an R117H mutation in exon 4 of the cystic fibrosis gene: three patients had a δF508/R117H cystic fibrosis genotype, and the fourth had an R117H/2322delG genotype.