The CFTR polymorphisms poly-T, TG-repeats and M470V in Chinese males with congenital bilateral absence of the vas deferens.

ABSTRACT

Congenital bilateral absence of the vas deferens (CBAVD) is a frequent cause of obstructive azoospermia, and mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene have also been frequently identified in patients with CBAVD. However, the distribution of the CFTR polymorphisms M470V, poly-T, TG-repeats and F508del mutation in the Chinese CBAVD population with presumed low cystic fibrosis (CF) frequency remains to be evaluated. Samples obtained from 109 Chinese infertile males with CBAVD and 104 normal controls were analyzed for the presence of CFTR (TG)m(T)n, M470V and F508del by PCR amplification followed by direct sequencing. Our study showed that the F508del mutation was not found in our patients. The 5T mutation was present with high frequency in Chinese CBAVD patients and IVS8-5T linked to either 12 or 13 TG repeats was highly prevalent among CBAVD patients (97.22% of 72 cases and 96.91% of 97 alleles with IVS8-5T). Moreover, a statistically significant relationship between TG12-5T-V470 haplotype and CBAVD was detected. This study indicated that the CFTR polymorphisms poly-T, TG-repeats and M470V might affect the process of CBAVD in the Chinese population.