Motor Impairment in Children with 16p11.2-Deletion and -Duplication Syndromes.

The present study sought to explore the motor phenotype of 16p11.2 deletion and duplication syndromes in a sample of probands (50.5% female), ranging in age from 6 months to 17 years. The extent and variability of motor dysfunction was assessed among carriers of 16p11.2 deletion and duplication syndromes, non-carrier siblings, and non-familial controls using several standardized performance- and informant-based measures. Analyses indicated that probands with either 16p11.2 deletion or duplication syndrome exhibited poorer motor performance compared to familial and non-familial controls. While deletion and duplication carriers performed similarly across several measures of fine-motor functioning, deletion carriers scored significantly lower than duplication carriers on the MABC-2, a comprehensive assessment of both gross- and fine-motor skills. Males and females with a 16p11.2 CNV performed worse on motor tasks compared to non-carrier controls, but there were no sex differences within carrier groups. Results underscore motor impairment as a clear feature of 16p11.2 deletion and duplication syndromes in infancy through adolescence. Motor functioning is discussed as a facet with strong evidence to support early identification practices of ASD.