Impact of Cystic Fibrosis Transmembrane Regulator (CFTR) gene mutations on male infertility

Objective. The aim of this study was to evaluate the prevalence of most common mutations and intron 8 5T (IVS8-5T) polymorphism of CFTR gene in Italian: a) azoospermic males; b) non azoospermic subjects, male partners of infertile couples enrolled in assisted reproductive technology (ART) programs. Material and methods. We studied 242 subjects attending our Andrology Unit (44 azoospermic subjects and 198 non azoospermic subjects, male partners of infertile couples enrolled in ART programs). Semen analysis, molecular analysis for CFTR gene mutations and genomic variant of IVS8-5T polymorphic tract, karyotype and chromosome Y microdeletions, hormonal profile (LH, FSH, Testosterone) and seminal biochemical markers (fructose, citric acid and L-carnitine) were carried out. Results. The prevalence of the common CFTR mutations and/or the IVS8-5T polymorphism was 12.9% (4/31 cases) in secretory azoospermia, while in obstructive azoospermia was 84.6% (11/13 cases; in these, the most frequent mutations were the F508del, R117H and W1282X). Regarding the non azoospermic subjects, the prevalence of the CFTR and/or the IVS8-5T polymorphism was 11.1% (11/99 cases) in severe dyspermia, 8.1% (6/74 cases) in moderate dyspermia and finally 4.0% (1/25 cases) in normospermic subjects. Conclusions. This study confirms the highly significant prevalence of CFTR mutations in males with bilateral absence of the vas deferens or ejaculatory ducts obstruction compared with subjects with secretory azoospermia. Moreover, the significant prevalence of mutations in severely dyspermic subjects may suggest the possible involvement of CFTR even in the spermatogenic process. This could explain the unsatisfactory recovery of sperm from testicular fine needle aspiration in patients affected by genital tract blockage.