Klinefelter 氏综合征或称原发性小睾丸症(Primary microrchidism),这种疾患最先由 Klinefelter 等所发现。在新生儿中,其发病率约为0.25～0.6％。这种个体的表现型为男性,其主要表现如下:男子乳房发育、睾丸小、精细管发育不全、无生育机能、尿内促性腺激素的分泌增加,17-酮类固醇含量下降,智力发育轻度阻滞等。多数患者的性染色质检查为阳性,染色体粗型为(47)XXY,虽然也有 Klinefelter’s syndrome, or primary microrchidism, was first discovered by Klinefelter et al. In neonates, the incidence of about 0.25 to 0.6%. The manifestations of such individuals are men, the main manifestations are as follows: male breast development, small testis, fine tube hypoplasia, no function of fertility, increased secretion of urinary gonadotropin, 17-keto-steroid decreased, mild mental development Blocking and so on. Most patients have a positive sex chromosome test, and the chromosome type is (47) XXY, although there are