Psychiatric and cognitive phenotype in children and adolescents with myotonic dystrophy

Myotonic dystrophy type 1 (DM1) is the most frequent inherited neuromuscular disorder. The juvenile form has been associated with cognitive and psychiatric dysfunction, but the phenotype remains unclear. We reviewed the literature to examine the psychiatric phenotype of juvenile DM1 and performed an admixture analysis of the IQ distribution of our own patients, as we hypothesised a bimodal distribution. Two-thirds of the patients had at least one DSM-IV diagnosis, mainly attention deficit/ hyperactivity disorder and anxiety disorder. Two-thirds had learning disabilities comorbid with mental retardation on one hand, but also attention deficit, low cognitive speed and visual spatial impairment on the other. IQ showed a bi-modal distribution and was associated with parental transmission. The psychiatric phenotype in juvenile DM1 is complex. We distinguished two different phenotypic subtypes: one group characterised by mental retardation, severe developmental delay and maternal transmission; and another group characterised by borderline full scale IQ, subnormal development and paternal transmission

Children with developmental coordination disorder in the child rehabilitation: Motor problems anf comordibity

The purpose of this study was to describe the developmental problems of children in school age, referred to the child rehabilitation centre because of clumsiness. The results show that 63% met the criteria for the classification of developmental coordination disorder and these children with DC:D show severe motor problems. A third also showed an abnormal handwriting, classified as dysgraphic. Though verbal intelligence performance on psychological tests was average, full-scale intelligence lies below average due to low performance intelligence. Scores on a language test for children were average. Parents as well as teachers acknowledged withdrawal (16%) and behavioural problems at home (51%) and in school (28%). Low self-esteem was perceived by 25% of children. In 50% DCD was combined with ADHD (attention deficit hyperactivity disorder). Special education facilities were needed in 30%. We conclude that children with DCD referred to a child rehabilitation centre may form a subgroup of severe DCD, that is often restricted not only by severe motor problems, but also by limitations in cognitive performance, ADD and a tendency towards internalising behaviour. Motor problems may serve as a symptom or signal of more complex developmental disorders and should be recognised at an early age. It is important to start early comprehensive intervention

Autistic traits in children with ADHD index clinical and cognitive problems

Traits of autistic spectrum disorders (ASD) occur frequently in attention deficit hyperactivity disorder (ADHD), but the significance of their presence in terms of phenotype and underlying neurobiology is not properly understood. This analysis aimed to determine whether higher levels of autistic traits, as measured by the Social Communication Questionnaire (SCQ), index a more severe presentation in a large, rigorously phenotyped sample of children with ADHD (N = 711). Regression analyses were used to examine association of SCQ scores with core ADHD features, clinical comorbidities and cognitive and developmental features, with adjustment for putative confounders. For outcomes showing association with total SCQ score, secondary analyses determined levels of differential association of the three ASD sub-domains. Results suggest that increasing ASD symptomatology within ADHD is associated with a more severe phenotype in terms of oppositional, conduct and anxiety symptoms, lower full-scale IQ, working memory deficits and general motor problems. These associations persisted after accounting for ADHD severity, suggesting that autistic symptomatology independently indexes the severity of comorbid impairments in the context of ADHD. Sub-domain scores did not show unique contributions to most outcomes, except that social deficits were independently associated with oppositional symptoms and repetitive behaviours independently predicted hyperactive-impulsive symptoms and motor problems. It would be worthwhile for clinicians to consider levels of socio-communicative and repetitive traits in those with ADHD who do not meet diagnostic criteria for ASD, as they index higher levels of phenotypic complexity, which may have implications for efficacy of interventions