Reciprocal translocation t(7;16)(q21.2;p13.3) in an infertile man

Abstract

Objective: To report the first case of reciprocal translocation t(7;16)(q21.2;p13.3) associated with male factor infertility.

Design: Case report.

Setting: University genetics laboratory and university andrology unit.

Patient(s): A 38-year-old man with infertility and oligoasthenoteratozoospermia, but otherwise healthy.

Intervention(s): Chromosome analyses from peripheral blood lymphocyte cultures using Giemsa (G)-banding (GTG) and C-banding (CBG) and fluorescent in situ hybridization (FISH) were performed.

Main outcome measure(s): Sperm count, motility, morphology, GTG and CBG banding, and FISH.

Result(s): We report an apparently unique reciprocal translocation t(7;16)(q21.2;p13.3) confirmed by FISH in an infertile man. Semen analyses showed oligoasthenoteratozoospermia, with sperm count ranging from 2 x 10(6)/mL to 5 x 10(6)/mL and head defects (98%) in sperm morphology.

Conclusion(s): In the present patient the breakpoint at 16p13.3 could have disrupted or harbored the PRM1, PRM2, or TNP2 genes responsible for the replacement of the histones involved in packaging the DNA into the sperm head. Resulting haploinsufficiency of these genes is likely to be the cause of sperm head defects and infertility in the patient. This case supports the opinion that alterations in the expression of protamine genes may be one of the causes of male factor infertility.