Ezeh U O, Modebe O
Department of Obstetrics and Gynecology, Jessop Hospital for Women, Sheffield, England.
Hum Biol. 1996 Aug;68(4):555-62.
Different proposals have been offered to explain the polymorphism of the sickle cell hemoglobin gene. One of these proposals (Eaton and Mucha 1971) suggested that differential fertility of male subjects with the sickle cell trait contributes to the persistence and stability of the sickle cell gene frequency. Eaton and Mucha claimed that oligospermia, 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 function, 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 mean serum concentration of testosterone, luteinizing hormone, follicle-stimulating hormone, and prolactin of both groups, measured by radio-immunoassay, were not statistically different from each other. Also, there was no detectable difference in any of the common indexes of semen quality between the two groups. The testicular volume index and several anthropometric indexes of subjects with the sickle cell trait and subjects with the normal hemoglobin genotype were also statistically similar. The results suggest that gonadal function is similar in adult males 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.
人们提出了不同的假说来解释镰状细胞血红蛋白基因的多态性。其中一种假说（伊顿和穆查，1971年）认为，具有镰状细胞性状的男性生育能力存在差异，这有助于镰状细胞基因频率的持续存在和稳定。伊顿和穆查声称，高热引起的少精子症在这些男性中是一个不太常见的问题，因为与正常基因型的男性相比，他们因疟疾感染引起的发热发作可能更轻微、持续时间更短。我们通过比较具有镰状细胞性状的成年男性和年龄匹配的正常血红蛋白基因型男性的睾丸功能、睾丸大小以及生殖激素的血清浓度，来寻找支持这一假说的证据。通过放射免疫测定法测得的两组男性的睾酮、促黄体生成素、促卵泡生成素和催乳素的平均血清浓度在统计学上没有差异。此外，两组之间精液质量的任何常见指标都没有可检测到的差异。具有镰状细胞性状的男性和具有正常血红蛋白基因型的男性的睾丸体积指数和一些人体测量指标在统计学上也相似。结果表明，正常基因型的成年男性和具有镰状细胞性状的成年男性的性腺功能相似。后一组中观察到的生育能力增加可能是由于性腺外因素。
