Assessment of sex chromosome aneuploidy in sperm nuclei from 47,XXY and 46,XY/47,XXY males: comparison with fertile and infertile males with normal karyotype

Sex chromosome aneuploidy was assessed in spermatozoa from a 47,XXY male an d a 46,XY/47,XXY male using three colour fluorescence in-situ hybridization (FISH) and compared with two control groups. The first group included subj ects of proven fertility and the second infertile males with normal constit utional karyotype. The frequencies of XX and YY disomic, XY hyperhaploid an d diploid spermatozoa were significantly increased in the 47,XXY male compa red to subjects from the two control groups (P < 0.0001). For the 46,XY/47, XXY sample, the same results were observed, except that the incidence of YY disomic spermatozoa did not differ significantly from the rate obtained in infertile patients. The frequency of sex chromosome aneuploidy did not dif fer significantly between the 47,XXY and the 46,XY/47,XXY males, except for XX disomic sperm nuclei which was higher in the 47,XXY patient. The freque ncy of chromosome 12 disomy was also increased in the two XXY individuals ( 0.42 and 0.49% respectively; P < 0.0001). The meiotic abnormalities observe d in the two XXY patients arose through segregation errors in XY germ cells . The increased number of meiotic nondisjunctions observed in the germ cell s of infertile males may be a common feature of the deficient oligo- or azo ospermic testis. Patients with Klinefelter's syndrome with oligozoospermia have an increased risk of both sex chromosome and autosome aneuploidy in th eir progeny.