Klinefelter症候群にかんする臨床的研究 3.Klinefelter症候群の出生時父母年齢,出生順位,同胞数,同胞性比,双生児頻度について

Abstract

In order to investigate biological factors in pathogenesis of Klinefelter's syndrome, 47 cases with XXY karyotype were studied as to parental age at birth, rank, number of sibship, sex ratio of sibship and incidence of twin in sibship. Maternal age at birth in Klinefelter's syndrome was 32.0±6.60 in average, being significantly higher than the national average (29.3±3.99). Distribution of the maternal age was bimodal, and relative risk rate of Klinefelter's syndrome increased after 35 of age. Paternal age at birth was 36.6±7.71 in average. Significance of this value was not clear because of lack of control. Birth rank did not differ from the general population. Number of sibship was 4.5 in average. Sex ratio of sibship was dominant in male. There was no case having twin in sibship.