Y-chromosome microdeletion and its effect on reproductive decisions in taiwanese patients presenting with nonobstructive azoospermia.

OBJECTIVES

To investigate the position, extent, and frequency of Y chromosome microdeletions in Taiwanese patients presenting with nonobstructive azoospermia, and to investigate the effect of microdeletions on reproductive decisions.

METHODS

We studied 176 consecutive men with azoospermia in our urology clinic. Polymerase chain reaction tests were performed in 94 patients with nonobstructive azoospermia, and a series of 27 sequence-tagged sites (STSs) mapped within intervals 5 and 6 of Yq11 was selected for analysis. Clinical genetics counseling was provided to couples with microdeletions, and these couples made their own choices about further treatment modalities.

RESULTS

Among 94 patients screened for microdeletion, 11 (11.7%) showed microdeletions of one or more STSs. One had a deletion confined to the azoospermia factor b (AZFb) region (encompassing the RBM gene). Two were found to have deletions of both the AZFb and AZFc regions. Eight patients had deletions in the AZFc region (encompassing the DAZ gene). Five had deletions distal to the DAZ gene family. One had multiple, noncontiguous deletions. In 8 patients with testicular histology available, a lack of genotype/phenotype correlation was noted. Of the 11 couples with deletions, 3 thought microdeletion was a serious defect and opted for an artificial insemination of donor or adoption, 5 chose intracytoplasmic sperm injection, and the other 3 decided to undergo treatment with Chinese medicinal herbs.

CONCLUSIONS

The most commonly deleted region in the Taiwanese population is AZFc. The genes implicated in Taiwanese spermatogenesis defects are the DAZ and RBM gene families. Twenty-seven percent of couples with microdeletions deferred assisted reproductive technologies because of concern about their underlying genetic defects.