Volume 12, Issue 6 (November 2010) 12, 819–826; 10.1038/aja.2010.58
Identification of the second CFTR mutation in patients with congenital bilateral absence of vas deferens undergoing ART protocols
Rossella Giuliani1, Ivana Antonucci2, Isabella Torrente3, Paola Grammatico4, Giandomenico Palka2,5, Liborio Stuppia2,6
1 Department of Clinical Sciences and Bioimages, ‘G. d’Annunzio’ University, Chieti-Pescara 66013, Italy
2 Department of Biomedical Sciences, ‘G. d’Annunzio’ University, Chieti-Pescara 66013, Italy
3 IRCCS CSS-Mendel Institute, Rome 00198, Italy
4 Medical Genetics Laboratory, Experimental Medicine Department, Sapienza, S.Camillo-Forlanini Hospital, University of Rome, Rome 00152, Italy
5 Human Genetic Division, Pescara Hospital, Pescara 65100, Italy
6 I.G.M. CNR, c/o IOR, Bologna 40136, Italy
Correspondence: Dr Liborio Stuppia,firstname.lastname@example.org
Received 2 March 2010; Revised 10 May 2010; Accepted 2 June 2010; Published online 26 July 2010.
Congenital bilateral absence of vas deferens (CBAVD) is a manifestation of the mildest form of cystic fibrosis (CF) and is characterized by obstructive azoospermia in otherwise healthy patients. Owing to the availability of assisted reproductive technology, CBAVD patients can father children. These fathers are at risk of transmitting a mutated allele of the CF transmembrane conductance regulator (CFTR) gene, responsible for CF, to their offspring. The identification of mutations in both CFTR alleles in CBAVD patients is a crucial requirement for calculating the risk of producing a child with full-blown CF if the female partner is a healthy CF carrier. However, in the majority of CBAVD patients, conventional mutation screening is not able to detect mutations in both CFTR alleles, and this difficulty hampers the execution of correct genetic counselling. To obtain information about the most represented CFTR mutations in CBAVD patients, we analysed 23 CBAVD patients, 15 of whom had a single CFTR mutation after screening for 36 mutations and the 5T allele. The search for the second CFTR mutation in these cases was performed by using a triplex approach: (i) first, a reverse dot-blot analysis was performed to detect mutations with regional impact; (ii) next, multiple ligation-dependent probe amplification assays were conducted to search for large rearrangements; and (iii) finally, denaturing high-performance liquid chromatography was used to search for point mutations in the entire coding region. Using these approaches, the second CFTR mutation was detected in six patients, which increased the final detection rate to 60.8%.
Keywords: congenital bilateral absence of vas deferens; cystic fibrosis transmembrane conductance regulator; male infertility