Correlation between genito-urinary anomalies, semen analysis and CFTR genotype in patients with congenital bilateral absence of the vas deferens.

OBJECTIVE

To evaluate the incidence of renal and seminal vesicle (SV) abnormalities, and the presence or absence of CFTR gene mutations, in a cohort of patients referred for congenital bilateral absence of the vas deferens (CBAVD).

PATIENTS AND METHOD

Forty-one patients with CBAVD, confirmed by surgical exploration, were evaluated by ultrasonography for renal and SV anomalies. Semen variables (pH, fructose level and ejaculate volume), sweat chloride levels and mutations of the 3, 4, 7, 9, 10, 11, 13, 14b, 17b, 19, 20 and 21 exons of the CFTR gene were determined.

RESULT

In eight patients with renal anomalies there were no detectable mutations of CFTR, compared with 23 in the 33 patients with no renal anomalies (P < 0.02). SV anomalies were not related to the presence or absence of mutations (11 of 23 vs 11 of 18), or in compound heterozygote patients carrying two mutations (eight of 13 vs three of 10). Semen variables (pH < 7.2, fructose < 1 g/L and ejaculate volume < 2 mL) did not differentiate patients with or without anomalies of the kidney, SV or with mutations, except in patients with a pH < 7.2 for which renal anomalies were less frequent (two of 25 vs six of 16, P < 0.05) and mutations more frequent (19 of 25 vs five of 12, P < 0.01).

CONCLUSION

Renal anomalies associated with CBAVD should be considered as supporting maldevelopment as a cause, but analysis of CFTR mutations in these cases should not be omitted. Unlike anomalies of the SV, a low ejaculate volume or low fructose level, a semen pH of < 7.2 is the only nonspecific variable in patients with CFTR mutations.