METHODS: In the present study, we performed whole-exome sequencing and co-segregation analysis in a Chinese pedigree involving two patients diagnosed with CAVD.
RESULTS: We identified a rare frameshift variant (NM_000492.3: c.50dupT;p.S18Qfs*27) and a frequent CBAVD-causing variant (IVS9-TG13-5T) in both patients. The frameshift variant introduced a premature termination codon and was not found in any public databases or reported in the literature. Co-segregation analysis confirmed these two variants were in compound heterozygous state. The other male members, who harbored the frameshift variant and benign IVS9-7T allele, did not have any typical clinical manifestations of CF or CAVD.
CONCLUSIONS: Our findings may broaden the mutation spectrum of CFTR in CAVD patients and provide more familial evidence that the combination of a mild variant and a severe variant in trans of CFTR can cause vas deferens malformation.