Altres ajuts: A. García-Peiró has a grant from the Càtedra de Recerca Eugin-UAB

Although several reports on male infertility suggest a relationship between chromosome 9 polymorphisms and infertility, the effects on the phenotype have not been extensively reported. In this study, an infertile patient was found to carry a 9qh+++ chromosome. The flow cytometric TUNEL assay and SCD test have been applied to characterize sperm DNA integrity. In order to assess its meiotic behaviour, synapsis, recombination, and aneuploidy, analyses have been also performed. Sperm DNA fragmentation (SDF) was 77.81% and 87% for the TUNEL and SCD tests, respectively. Ninety-two percent of pachytene cells analyzed showed meiotic abnormalities. The mean number of MLH1 foci per pachytene in the control group was higher (49) than the mean found in the 9qh+++ patient (38) (P <.0001). In spermatozoa, significant increases of disomy rates were observed for chromosome 18 and for the sex chromosomes (P <.0001). These disturbances could be present in other male carriers of a less marked 9qh+.