Coordination difficulties, IQ and psychopathology in children with high-risk Copy Number Variants

Background The prevalence and impact of motor coordination difficulties in children with Copy Number Variants that are associated with high risk of neurodevelopmental disorder (ND-CNVS) remain unknown. The present study aims to advance understanding of motor coordination difficulties in children with ND-CNVs and establish relationships with IQ and psychopathology. Methods 169 children with a ND-CNV (67% male, median age 8.88 years, range 6.02-14.81) and 57 closest-in-age unaffected siblings (controls; 55% male, median age 10.41 years, SD=3.04, range 4.89-14.75) were assessed with the Developmental Coordination Disorder Questionnaire, alongside psychiatric interviews, and standardised assessments of IQ. Results 91% of children with an ND-CNV screened positive for coordination problems, compared to 19% of unaffected sibling controls (OR=42.53, p<.001). There was no difference in coordination ability between ND-CNV genotypes (F=1.47, p=.184). Poorer motor coordination in the ND-CNV group was associated with greater numbers of ADHD (p=.021) and autism spectrum disorder trait (p<.001) symptoms, along with lower full-scale (p=.011), performance (p=.015), and verbal IQ (p=.036). Mediation analysis indicated that coordination ability was a full mediator of anxiety symptoms (69% mediated, p=.012), and a partial mediator of ADHD (51%, p=.001) and ASD trait symptoms (66%, p<.001) along with FSIQ (40%, p=.002) PIQ (40%, p=.005) and VIQ (38%, p=.006) scores. Conclusions The findings indicate that poor motor coordination is highly prevalent and closely linked to risk of mental health disorder and lower intellectual function. Future research should explore whether early interventions for poor coordination ability could ameliorate neurodevelopmental risk more generally.