Preoperative screening for genetic abnormalities in men with nonobstructive azoospermia before testicular sperm extraction.

PURPOSE

Men with nonobstructive azoospermia may be treated with testicular sperm extraction and assisted reproduction. However, in men with severely impaired spermatogenesis genetic anomalies may be a cause of low sperm production. We present the results of genetic screening of men with nonobstructive azoospermia who are testicular sperm extraction candidates.

MATERIALS AND METHODS

Genetic evaluation was performed in a sequential series of 190 men with nonobstructive azoospermia who were candidates for testicular sperm extraction, including standard peripheral karyotypic analysis and detailed polymerase chain reaction based evaluation of the Y chromosome. All men found to harbor genetic defects were referred for genetic counseling.

RESULTS

Of the 190 patients 33 (17%) had genetic abnormalities. Of the 101 men who underwent karyotyping 21 (21%) had cytogenetic abnormalities, including 13 with Klinefelter's syndrome. Of the 183 men who underwent Y chromosome partial deletion analysis defects were detected in 17 (9%). Five men had karyotypic anomalies as well as evidence of partial Y chromosome deletions on polymerase chain reaction based analysis. Genetic counseling was done in 31 men with defects before testicular sperm extraction. Knowledge of the specific genetic defect resulted in a change of clinical management in 7 of the 33 couples (21%) in which the man had a genetic abnormality.

CONCLUSIONS

These results indicate that preoperative genetic screening is important in men with nonobstructive azoospermia who are candidates for testicular sperm extraction with intracytoplasmic sperm injection. Genetic testing provides men with reassuring etiological information regarding the infertile condition as well as a means to assess the risk of passing infertility traits to male offspring. It allows specific preimplantation genetic testing of embryos during assisted reproduction to minimize the risk of transmitting genetic defects to offspring.