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.