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 c haracteristics of patients with congenital bilateral absence of the vas def erens (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 expl oration 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. Semi nal vesicles were bilaterally absent in 28% of patients. No CFTR gene mutat ion or 5T allele was detected in 24.5% of the patients. Two CBAVD patients with renal agenesis carried a CFTR gene mutation (Delta F508/5T-9T and R117 G/7T-9T). CBAVD patients who have both a semen volume of less than or equal to1.0 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 pa tients. Semen volume of <less than or equal to>1.0 mL and semen pH of <7.0 in CBAVD patients were associated with a higher risk of severe CFTR gene mu tations. Patients with CBAVD and renal agenesis should be screened for CFTR gene mutations before assisted reproductive techniques are used. (Fertil S teril(R) 2000;74:1164-74. (C) 2000 by American Society for Reproductive Med icine).