Emotional and behavioural phenotypes in young people with neurodevelopmental CNVs

Background: A number of disorders caused by copy number variants (CNVs) are associated with a high risk of neurodevelopmental and psychiatric disorders and cognitive impairments (ND-CNVs). Few studies of ND-CNVs have investigated the emotional and behavioural problems that are important outcomes in young people with developmental and intellectual disabilities using appropriate measures. Methods: 322 young people with 13 ND-CNVs across eight loci (mean age:9.79 years, range:6.02-17.91, 66.5% male) took part in the study. Primary carers completed the Developmental Behaviour Checklist (DBC). Results: Sixty-seven percent of individuals with an ND-CNV screened positive for clinically significant difficulties. Young people from families with higher incomes (OR=0.71, CI=0.55 - 0.92, p=.009) were less likely to screen positive. Young people born after prolonged labour (OR=2.87, CI=1.18-8.13, p=.030) were more likely to screen positive. The rate of difficulties differed depending on ND-CNV genotype (Deviance=25.83, p=.011), with the lowest rate in 22q11.2 deletion (46%) and the highest in 1q21.1 deletion (87.5%). Individuals with inherited ND-CNVs had greater difficulties (F=6.54, df=1, p=.012, np2=.050), including higher self-absorbed (F=5.01, df=1, p=.027, np2=.039) and communication disturbance scores (F=9.13, df=1, p=.003, np2=.068). Specific patterns of strengths and weaknesses were found for different ND-CNV genotypes. However, ND-CNV genotype explained no more than 7-16% of variance, depending on subdomain. Conclusions: Behavioural and emotional problems are common in young people with ND-CNVs. The ND-CNV specific patterns we find can provide a basis for more tailored support. More research is needed to better understand the variation in behavioural and emotional problems not accounted for by genotype.