MALE-INFERTILITY CAUSED BY CONGENITAL BIL ATERAL ABSENCE OF VAS-DEFERENS - NEW CLINICAL ASPECT OF CYSTIC-FIBROSIS

Congenital bilateral absence of vas deferens causes male excretory inf ertility and represents 1 to 2% of male infertility. Because of a geno typic similarity with cystic fibrosis, the possible in vitro fertiliza tion with epididymal sperm requires careful genetic counselling. We st udied genotype, sweat chloride concentration, respiratory function tes ts, sinus abnormalities, pancreatic and hepatic functions in 22 subjec ts with congenital bilateral absence of vas deferens. Among them, four were compound heterozygotus, all of them with the R117H mutation. Ten had a positive sweat test, one of them also being compound heterozygo tus. Congenital bilateral absence of vas deferens and double mutation or positive sweat test led to high probable cystic fibrosis diagnosis in 13 subjects. Six subjects were heterozygotus for one cystic fibrosi s mutation, criterium which is not sufficient for cystic fibrosis diag nosis; five of them had sinus abnormalities, present in 11 of the 22 s ubjects. Only three patients had no mutation nor sweat chloride abnorm alities. This work confirms the high frequency of cystic fibrosis muta tions in males with congenital bilateral absence of vas deferens, with a higher frequency of positive sweat test than in other publication, and a high frequency of sinus abnormalities. This monosymptomatic phen otype of cystic fibrosis suggests new hypotheses for a relationship be tween genotype and phenotype.