Plasmatic testosterone values in 105 Klinefelters.

Clinical, spermiologic and karyologic examinations and determinations of plasmatic testosterone were performed in a group of 105 chromatin-positive patients aged 16 to 45 years. A comparison with a control group of 108 somatosexually well developed and fertile men at the age of 21 to 55 years has established that in the Klinefelter's syndrome the male sex hormone level in the blood was highly significantly lower. Whereas in the control group the male sex hormone values in the blood were dependent on age, it was not possible to prove any dynamic changes in the process of ageing between 21 and 45 years in chromatin-positive patients. A comparison of some phenotypical and laboratory findings in the various chromosomal variants of Klinefelter's syndrome shows that comparatively the least changes were found in patients with a mosaic of 46,XY/47,XXY.