MICRODELETIONS IN THE Y-CHROMOSOME OF INFERTILE MEN

Background Some infertile men with azoospermia or severe oligospermia have small deletions in regions of the Y chromosome. However, the freq uency of such microdeletions among men with infertility in general is unknown. We sought to determine the prevalence of Y-chromosome microde letions among infertile men and to correlate the clinical presentation of the men with specific deletions. Methods We studied 200 consecutiv e infertile men. Each man was evaluated comprehensively for known caus es of infertility, and Y-chromosome microdeletions were studied with u se of the polymerase chain reaction to amplify specific regions of the chromosome. The Y chromosomes of 200 normal men were also analyzed. R esults Fourteen infertile men (7 percent) and four normal men (2 perce nt) had microdeletions of the Y chromosome. Nine of the infertile men had azoospermia or severe oligospermia (sperm concentration, <5 millio n per milliliter), four had oligospermia (sperm concentration, 5 milli on to <20 million per milliliter), and one had normospermia (sperm con centration, greater than or equal to 20 million per milliliter). The s ize and location of the deletions varied and did not correlate with th e severity of spermatogenic failure. The fathers of six infertile men with microdeletions were studied; two had the same deletions as their sons, and four had no deletions. Conclusions A small proportion of men with infertility have Y-chromosome microdeletions, but the size and p osition of the deletions correlate poorly with the severity of spermat ogenic failure, and a deletion does not preclude the presence of viabl e sperm and possible conception. (C) 1997, Massachusetts Medical Socie ty.