Abstract
BACKGROUND: The aim was to gain a UK national sample of people with Rett syndrome (RTT) across the age range and compare their characteristics using a variety of relevant behavioural measures with a well-chosen contrast group. METHODS: The achieved sample was 91 girls and women, aged from 4 to 47 years, of whom 71 were known to be MECP2 positive. The contrast group (n = 66), matched for age, gender, language and self-help skills, comprised individuals with six other syndromes associated with intellectual disability. Parental questionnaire measures of RTT specific characteristics, impulsivity, overactivity, mood, interest and pleasure, repetitive behaviour and self-injury were administered. RESULTS: Hand stereotypies, breathing irregularities, night-time unrest and anxiety or inappropriate fear were commonly reported among the RTT sample. Problems of low mood were also reported as common. However, mood and interest and pleasure were no lower than found in the contrast group. In addition, self-injury was lower than in the contrast group and was associated with factors found to predict self-injury in other groups of people with severe intellectual disabilities. CONCLUSIONS: There is variability in the manifestation of problem behaviours potentially associated with the syndrome across individuals, with some more severely affected in most areas than others. Some of this variability appears to be underpinned by genetic mutation.