Table 1

Summary of the X chromosome inactivation tests performed on RTT mothers and their daughters (for the four familial cases without MECP2 mutation reported in this study), CEPH controls, sporadic cases of RTT, and ATR-X carrier females. Females were scored as “skewed” when the ratio of XCI was above 95:5

Number tested Skewed Not skewed % skewed Mother to daughter transmission (%)
RTT mothers440100100
RTT daughters86275
CEPH controls52547101
RTT sporadic434399