Congenital bilateral absence of the vas deferens: clinical characteristics, biological parameters, cystic fibrosis transmembrane conductance regulator gene mutations, and implications for genetic counseling.

OBJECTIVE: To evaluate relationships between the phenotypic and genotypic characteristics of patients with congenital bilateral absence of the vas deferens (CBAVD).
DESIGN: Retrospective study.
SETTING: A university hospital urology-andrology department. PATIENT(S): Forty-one men with CBAVD. INTERVENTION(S): CBAVD was diagnosed during surgical and/or ultrasound exploration of the vasa deferentia (VD) (n = 39), or on the basis of impalpable scrotal VD (n = 2). MAIN OUTCOME MEASURE(S): History, clinical and seminal characteristics, and cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations including IVS-8 polyT analysis. RESULT(S): A palpable scrotal vas deferens was present as a fibrous cord or nonpermeable duct in 13% of patients undergoing surgical exploration. Seminal vesicles were bilaterally absent in 28% of patients. No CFTR gene mutation or 5T allele was detected in 24.5% of the patients. Two CBAVD patients with renal agenesis carried a CFTR gene mutation (DeltaF508/5T-9T and R117G/7T-9T). CBAVD patients who have both a semen volume of < or =1.0 mL and a semen pH of < 7.0 have a significantly higher risk of severe CFTR gene mutation (OR = 9.12 [95% CI = 1.81-49.50]). CONCLUSION(S): A palpable scrotal vas deferens was found in 13% of CBAVD patients. Semen volume of < or =1.0 mL and semen pH of < 7.0 in CBAVD patients were associated with a higher risk of severe CFTR gene mutations. Patients with CBAVD and renal agenesis should be screened for CFTR gene mutations before assisted reproductive techniques are used.