Analysis of human spermatozoa for Y chromosomal nondisjunction.
The YFF sperm assay, which is a quantification of the incidence of sperm with two fluorescent bodies (YFF = two fluorescent bodies), was performed to measure Y chromosomal nondisjunction. Three categories of human subjects were analyzed: 1) nonexposed, 2) exposed to antineoplastic agents - ie, chemo- and radiation therapy, and 3) dibromochloropropane (DBCP)-exposed. The nonexposed individuals demonstrated a relatively constant mean YFF value of 1.3%, which was consistent with historical controls in this laboratory and with the results of other investigators. Further, a one-way analysis of variance among the means of the control samples revealed no statistical differences either between these men or within each man's samples. The individuals exposed to antineoplastic agents showed a three- to four-fold increase in the incidence of YFF sperm three to six weeks after the initiation of exposure to Adriamycin and X-irradiation. The maximum percentages of YFF per 1,000 sperm for each individual in this exposed group was analyzed by Wilcoxon's distribution free rank sum test using a one-sided alternative. The exposed individuals' maximum YFF percentages were statistically significantly increased when compared to the maximum YFF values of the nonexposed controls. The individuals exposed to the nematocide DBCP also exhibited a statistically significant increase in the number of sperm containing two Y chromosomes as determined by chi-square analysis with one degree of freedom (P less than 0.01). Data presented herein show statistically significant increases in the incidence of double Y chromosomes as measured by the presence of YFF sperm following exposure to Adriamycin, X-irradiation, and DBCP. It is suggested that men who have a history of antineoplastic therapy could be evaluated for evidence of Y-Y nondisjunction with this method. In the event of an increased YFF sperm level, genetic counseling and amniocentesis should be made available to the spouse where pregnancy has occurred. Further, because this procedure measures gametic mutation, is relatively simple, and is noninvasive, it should be considered for inclusion as part of a battery of medical tests for monitoring industrial populations.