Congenital bilateral absence of the vas deferens (CBAVD) is a frequent cause of obstructive azoospermia, and caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.
Effects of cystic fibrosis and congenital bilateral absence of the vas deferens-associated mutations on cystic fibrosis transmembrane conductance regulator-mediated regulation of separate channels.
In monosymptomatic forms of cystic fibrosis such as congenital bilateral absence of vas deferens, variations in the TG(m) and T(n) polymorphic repeats at the 3' end of intron 8 of the cystic fibrosis transmembrane regulator (CFTR) gene are associated with the alternative splicing of exon 9, which results in a nonfunctional CFTR protein.
A T3 allele in the CFTR gene exacerbates exon 9 skipping in vas deferens and epididymal cell lines and is associated with Congenital Bilateral Absence of Vas Deferens (CBAVD).
Furthermore, we have described the segregation of CFTR haplotypes in the family of one CBAVD male; in this family are two male siblings, with identical CFTR loci but displaying different phenotypes, one of them being fertile and the other sterile.
The high frequency of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene mutation p.Arg117His in patients with congenital bilateral absence of the vas deferens (CBAVD) and in newborns screened for CF has created a dilemma.
To identify such factors, we report here the genetic analysis of a polymorphic locus, M470V, located in exon 10 of the CFTR gene in 60 patients with CBAVD, compared to a normal control population.
To identify CFTR promoter region mutations in Chinese CBAVD patients, fragments 1.4 kb upstream of the ATG start codon of the CFTR gene were sequenced in 66 Chinese patients with CBAVD and compared to the corresponding sequences from 60 healthy subjects and sequence data present in the NCBI database.
We screened for the CFTR gene mutation in a Caucasian father with congenital bilateral absence of the vas deferens (CBAVD), a Taiwanese mother, and twins resulting from an intracytoplasmic single sperm injection (ICSI) procedure.
We found that R74Wcystic fibrosis transmembrane conductance regulator appears to be a polymorphism, while D1270Ncystic fibrosis transmembrane conductance regulator could be responsible for the congenital bilateral absence of the vas deferens phenotype.
This case report documents for the first time a male phenotype associated with the p.P841R mutation and underlines the difficulties in counseling a man with congenital bilateral absence of the vas deferens carrying uncommon mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene before ICSI.
Genetic testing of the cystic fibrosis transmembrane conductance (CFTR) gene is currently performed in couples undergoing assisted reproduction techniques (ART), because of the high prevalence of healthy carriers in the population and the pathogenic relationship with congenital bilateral absence of vas deferens (CBAVD).