PRE NATAL TESTOSTERONE LEVELS IN XXY AND XYY MALES

Abstract

It has been postulated that behavioural differences between normal males and those with an additional X or Y chromosome may be related to hormonal variations pre or post natally. We have previously demonstrated that XXY males have a testosterone surge in the neonatal period (1) and that during childhood salivary testosterone levels are slightly higher than in control males (2).The pre-natal hormone status is now investigated using amniotic fluid obtained at ante natal diagnosis between 16 and 20 weeks gestation age in a collaborative project between the Departments of Medical Genetics of Guy's Hospital, London, Oxford, Glasgow and Edinburgh.The (geometric) mean testosterone levels and ranges (p mol/L) were XY 433.5, range 165-1027 (n=25); XYY 500.0, range 224-1092 (n=15); XXY 419.8 range 87-1021 (n=17); XX 146.9, range 41-474 (n=13).After log transformation, using the t test no significant differences were found between XY, XYY and XXY males but females had lower testosterone levels (p<0.001). These findings give no support to the hypothesis that pre-natal testosterone levels contribute to later behavioural characteristics.1 Ratcliffe SG. Proc Roy Soc Med, 1976, 69, 189-191.2 Ratcliffe SG. Butler GE, Jones M. BDOAS, 26, 1-44.