The association between behavior and genotype in Rett syndrome using the Australian Rett Syndrome Database

This study compared the behaviour profile of cases in the Australian Rett Syndrome Database (ARSD) with those in a British study using the Rett Syndrome Behaviour Questionnaire (RSBQ) then examined behavioural patterns as measured by the RSBQ by genetic status. There were 145 Australian cases meeting the criteria for the first arm of the study and 135 for the second arm. Comparison of the scores obtained from the British and Australian cohorts indicated that the RSBQ was a satisfactory measure for describing behaviours in Rett syndrome (RS). Overall, there were some differences amongst the behaviour patterns of cases with the well-known common mutations. Fear/anxiety was more commonly reported in those with R133C and R306C. Those with the R294X mutation were more likely to have mood difficulties and body rocking but less likely to have hand behaviours and to display repetitive face movements. In contrast, hand behaviours were more commonly reported in those with R270X or R255X. We found the RSBQ is an appropriate instrument for measuring behaviour in girls with RS. Some behaviours differ according to genetic mutation but there is both inter and intra mutation variation in behaviour and there is a need for larger studies involving international collaboration to improve statistical power.