Approximately 0.2% to 0.3% of newborn male infants are sex-chromatin positive.19,4,18 Therefore they probably represent future cases of Klinefelter's syndrome. In contrast to this high frequency of sex-chromatin positive males is the scarcity of the prepubertal diagnosis of the XXY patient.
Usually children who later develop the Klinefelter's syndrome show no malformations betraying the abnormal chromosomal state. In two cases, however, the presence of hypospadias led to the finding of the XXY sex chromosome pattern at an early age.9,10
We recently had the opportunity to study a boy with hypospadias and XXY karotype.
Report of a Case
A 4-year-old boy was referred in November, 1963, to The Cincinnati Children's Hospital for chromosomal analysis. He had been born in August, 1959, with a rather severe hypospadias, the opening of the urethra being at the base of the penis. He had a bifid scrotum in which both testes were felt;
PASSARGE E, THOMPSON JN. Autoradiography in a Boy With XXY Karyotype. Am J Dis Child. 1964;108(2):184-188. doi:10.1001/archpedi.1964.02090010186012