Clinical and prognostic importance of chromosomal abnormalities, Y chromosome microdeletions, and CFTR gene mutations in individuals with azoospermia or severe oligospermia

Aim: To illustrate the importance of genetic screening in the assessment of fertility and the correct diagnosis in patients with azoospermia or severe oligospermia. Materials and methods: This study examined 500 patients with reproductive failure, having fewer than 5 million sperm/mL detected in at least 2 consecutive spermiograms, who presented at a medical genetics polyclinic between 2008 and 2012. Metaphase preparations obtained from cell cultures were stained by trypsin-Giemsa banding. After DNA isolation, Y chromosome loci, including AZFa (SY84, SY86), AZFb (SY127, SY134), AZFc (SY254 SY255), and AZFd, were amplified by polymerase chain reaction using specific primers. Thirty-five patients with congenital unilateral absence of the vas deferens or congenital bilateral absence of the vas deferens (CBAVD) and a positive cystic fibrosis family history were evaluated for cystic fibrosis transmembrane conductance regulator gene mutations. Results: No chromosomal abnormalities were noted in 440 (88%) of the 500 patients, whereas structural or numerical chromosomal abnormalities were detected in 60 patients (12%). Individuals with Y deletions made up 5.6% (n = 28) of the study sample. Three patients with no AZF deletion or chromosomal abnormality, but with CBAVD, were heterozygous for I148T, G1130A, or IVS3 406-3T> C mutations. Conclusion: This study shows that genetic testing can make an important contribution to the treatment of patients planning in vitro fertilization due to azoospermia or severe oligospermia.