IS THERE INCREASED FERTILITY IN ADULT MALES WITH THE SICKLE-CELL TRAIT

Different proposals have been offered to explain the polymorphism of t he sickle cell hemoglobin gene. One of these proposals (Eaten and Much a 1971) suggested that differential fertility of male subjects with th e sickle cell trait contributes to the persistence and stability of th e sickle cell gene frequency. Eaten and Mucha claimed that oligospermi a, induced by hyperpyrexia, is a less common problem in these subjects because they probably have milder and shorter episodes of fever from malaria infection than subjects with a normal genotype. We have looked for evidence to support this hypothesis by comparing the testicular f unction, testicular size, and serum concentrations of the reproductive hormones in adult male subjects with the sickle cell trait and in an age-matched group of subjects with normal hemoglobin genotype. The mea n serum concentration of testosterone, luteinizing hormone, follicle-s timulating hormone, and prolactin of both groups, measured by radioimm unoassay, were not statistically different from each other. Also, ther e was no detectable difference in any of the common indexes of semen q uality between the two groups, The testicular volume index and several anthropometric indexes of subjects with the sickle cell trait and sub jects with the normal hemoglobin genotype were also statistically simi lar. The results suggest that gonadal function is similar in adult mal es with the normal genotype and those with the sickle cell trait. Any increase in fertility observed in the latter group is probably due to extragonadal factors.