P12 Neurobehavioural disorders in Duchenne muscular dystrophy

Abstract

Abstract Variable neurobehavioural disorders and IQ one SD below average are recognised comorbidities in Duchenne muscular dystrophy (DMD), reflecting the disrupted expression of different length dystrophin isoforms in the brain, based on the dystrophin gene mutation site. Following a screening of 84 DMD boys with validated questionnaires, we previously reported 15 with severe learning disability and 41 with scores predictive of autistic spectrum disorder (ASD). Attention deficit and hyperactivity disorder (ADHD) traits, conduct and emotional problems were also described. Overall, a higher proportion of boys affected had mutations towards the 3’ end of dystrophin. We performed targeted neuropsychological assessments including: Wechsler Intelligence Children Scale-IV (WISC-IV), Developmental Dimensional and Diagnostic Interview (3Di), Conners-3 Questionnaires, Child Behaviour Checklist (CBCL). We found marked unevenness of performance on the WISC-IV. Eight out of 12 boys had significant difference between verbal comprehension (VCI) and perceptual reasoning (PRI), with VCI more compromised. Eight out of 19 met criteria for ASD on the 3Di. In 5 boys with ASD the CBCL showed higher scores for internalising and externalising difficulties compared to non-ASD. There were associations between lower IQ and autistic social communication difficulties. On the Conners 6/17 boys met criteria for hyperactivity and 7 for inattention problems. There was a strong association between ASD and severe ADHD symptoms of hyperactivity (OR = 22.5) and inattention (OR = 54). There was a trend towards children with mutations towards the 3’ end of the gene, having a greater chance of ASD (OR = 3.4). In our on-going study, neurobehavioural disorders emerged as important facets in DMD, with confirmed ASD prevalence rates much higher than the general population. Whilst further exploring the role of dystrophin in the brain, children with DMD should be provided with neurobehavioural-targeted support.