ESTIMATES OF ANEUPLOIDY USING MULTICOLOR FLUORESCENCE IN-SITU HYBRIDIZATION ON HUMAN SPERM

Single color fluorescence in situ hybridization (FISH) has been utiliz ed on sperm to estimate nondisjunction rates for chromosomes 1, 12, 15 , 16, X and Y. Using single-color FISH, one cannot distinguish nonhybr idization from nullisomy nor disomy from diploidy. In order to provide an internal control, a multicolor FISH strategy was employed. Satelli te probes specific for 13 human chromosomes were used on multiple seme n samples from two normal donors. Two or three probes were hybridized simultaneously and scored by two independent observers. Over all exper iments, 40,641 sperm were analyzed. The majority of autosomes had no s ignificant difference in aneuploidy between chromosomes or between don ors. However, a significant difference was observed for chromosome 18 between donors (chi(2)(2) = 7.078, 0.025 < P < 0.05). Additionally, no significant difference was found between donors for sex chromosome an euploidy. The frequency of sex chromosome aneuploidy was similar to th at seen in paternally derived 47,XXY and 47,XYY conceptuses. Furthermo re, 0.15% of sperm were found to be diploid. Based on the results of t his study, as much as 19% of all sperm may be chromosomally abnormal. This method proved to be useful for determining aneuploidy of human ch romosomes in sperm and valuable in exploring whether individual differ ences of nondisjunction exist.