CONGENITAL UNILATERAL ABSENCE OF THE VAS-DEFERENS - A HETEROGENEOUS DISORDER WITH 2 DISTINCT SUBPOPULATIONS BASED UPON ETIOLOGY AND MUTATIONAL STATUS OF THE CYSTIC-FIBROSIS GENE

A total of 21 infertile men with congenital unilateral absence of the vas deferens (CUAVD) were studied to determine if this disorder involv es mutations in the cystic fibrosis (CF) gene. This hypothesis derives from previous work which has established the genetic commonality of C F and congenital bilateral absence of the vas deferens (CBAVD), Both C F and CBAVD may result from compound heterozygosity for CF mutations. In our patients with unilateral vasal aplasia, 12 had anatomically com plete and patent vasa deferentia on the contralateral side, i,e. side of the scrotally palpable vas, No CF mutations were detected in this s ubgroup. The remaining nine patients had a non-iatrogenic occlusion of the contralateral vas at either the inguinal or pelvic level, In this subgroup, eight out of nine (89%) had a mutation detected in one of t heir two CF genes. This is the first study to define accurately the cl inically and anatomically heterogeneous nature of CUAVD and to begin t o clarify the genetic basis of unilateral absence of the vas deferens.