High incidence of sperm aneuploidy revealed by array CGH in oligoasthenoterato-zoospermic (OAT) patients

Background: Aneuploidy is a main cause of miscarriage and implantation failure whilst contribution of sperm aneuploidy in sterility is not well defined. High incidence of aneuploidy has been reported in OAT spermatozoa using fluorescence in situ hybridization (FISH). OAT is associated with lower pregnancy and implantation rates. Limited number of chromosomes is an inherent disadvantage of FISH studies.Objective: All chromosomes have not been studied in spermatozoa from OAT patients simultaneously. We investigated comprehensive aneuploidy screening of spermatozoa in OAT by array comparative genomic hybridization (aCGH).Materials and Methods: Four severe OAT patients without Y chromosome microdeletions with normal blood karyotype and history of implantation failure were enrolled. The female partners were healthy aged <36. Illumina 24 sure platform aCGH was employed for three samples of each patient containing 2 spermatozoa. Depending on the aneuploidies found by aCGH, FISH was utilized to find the magnitude of the detected abnormalities in total population of spermatozoa.Results: Aneuoploidy was detected by aCGH in 82% of samples ranged 1-6 chromosomes per patient. The most frequent ones were chromosomes 8, 21(3 of 4 patients; 36.4% and 45.5% of samples, respectively). We observed abnormalities that hardly ever considered in FISH studies of sperm such as chromosomes 19 and 20. Range of 782-1286 sperm per patient were scored in FISH, the most frequent abnormalities were disomy of chromosomes 13, 20, 22 and X/Y with mean rates of 10.9%, 6.2%, 5.2% and 5.6%, respectively and total aneuploidy was 47.55-81.6%.Conclusion: Both aCGH and FISH revealed incident aneuploidy in OAT spermatozoa. Aneuploidies of the single sperm seem to be independent of frequent aneuploidies in total sperm population. Regarding the high incidence of aneuploidies in severe OAT, comprehensive preimplantation aneuploidy screening should be more investigated in OAT.

کلیدواژه ها:

Sperm ، Aneuploidy ، Array CGH ، FISH ، Oligoasthenoteratozoospermia