Autistic-like behaviour profile and psychiatric morbidity in Fragile X Syndrome: a prospective ten-year follow-up study.

In subjects with Fragile X Syndrome (FXS), the mutation of Fragile X Mental Retardation Type 1 ( FMR-1) gene at Xq27.3 predisposes to Mental Retardation (MR), autistic-like behaviour and to a variety of psychiatric syndromes. However, the longitudinal course of autistic-like behaviour profile and psychiatric morbidity is untested. In this study, we followed up people with FXS for 10 years to establish the stability of their autistic- like behaviour profile and psychiatric morbidity. The autisticlike behaviour profile was assessed using Brief Disability Assessment Schedule (B-DAS) and relevant items from Handicaps, Behaviour and Skills (HBS) Schedule. The psychiatric morbidity was assessed using data from the case notes, Mini Psychiatric Assessment Schedule for Adults with Developmental Disability (Mini PAS-ADD) and clinical interview. Our findings suggest that the autistic-like behaviour pattern is a stable phenotypic feature of FXS, but for increase in resistance to change over time. There is a tenfold increase in the prevalence of psychiatric morbidity in FXS compared to the general population, which does not increase significantly over time.