Motor nerve conduction in 47, XXY and 48, XXYY males, and 47, XXX and 45, X females

Measurements were made of the maximum motor nerve conduction in the median and ulnar nerves of the right forearm for the four sex chromosomally abnormal groups 47, XXY and 48, XXYY males, 47, XXX and 45, X females. The results obtained were compared with male and female control groups (a) from the general population and (b) from a subnormality hospital. No significant differences were detected between the corresponding results for 47, XXY males and subnormal males. The results for the 47, XXY males were different from those for normal and subnormal females, except in the case of motor conduction in the median nerve for the subnormal female group. There is a suggestion of marked differences in motor conduction and distal latency in 48, XXYY males when compared to the two male control groups. 47, XXX females showed significant differences in motor conduction and distal latency when compared to normal females, but not when compared to subnormal females. No significant differences were detected between 45, X females and normal females for any of the variables measured.