Is There a Genetic Cause Behind Early Onset Psychosis in Children?

Children and adolescents with a psychotic diagnosis should be evaluated using autism spectrum disorder (ASD) genetic screening, given the high genetic burden from rare copy number variants (CNVs) observed among these 2 populations. These are the findings of a study published in the American Journal of Psychiatry.

Early onset psychosis prior to 13 years of age is associated with higher burden from rare CNVs compared with patients with adult-onset illness. Previous research identified that up to 15% of children with ASD carry deleterious genetic mutations. Given the high prevalence of genetic anomalies among both patient populations, researchers of the current study sought to evaluate whether there was evidence of similar genetic perturbations among children with early onset psychosis or ASD.

Data from the early onset psychosis cohort (n=137) were sourced from the Developmental Neuropsychiatry Program at Boston Children’s Hospital; data from 2 early onset psychosis cohorts were from the Simons Simplex Collection (SSC; n=2585) and the MSSNG database (n=3,171); and data from 3 control cohorts were from IMAGEN (n=51,802), Generation Scotland (n=514,160), and the Lothian Birth Cohort (n=5554). CNVs and CNV Risk Scores (CRSs) were compared between groups.

After filtering data, the early onset psychosis (n=137), ASD (n=5540), and control (n=16,504) cohorts included 64%, 83%, and 42% boys or men; 12%, 17%, and 3% had intellectual disability; there were 5, 83, and 130 recurrent deletion carriers; and 6, 114, and 144 recurrent duplication carriers, respectively.

The prevalence of recurrent CNV carriers was higher among the early onset psychosis cohort compared with children with ASD (odds ratio [OR], 2.42; 95% CI, 1.16-4.57; P =.02) or control individuals (OR, 5.19; 95% CI, 2.50-9.75; P =2×10^-5). Specifically, 3 CNVs were enriched among the early onset psychosis group compared with control individuals (1q21.1, 16p13.11, 22q11.2).

The early onset psychosis group was associated with higher CRSs for deletions (OR, 1.30; 95% CI, 1.26-1.35; P =9×10^-8) and duplications (OR, 1.09; 95% CI, 1.06-1.12; P =.02) compared with control individuals. Similar trends in deletions (OR, 1.24; 95% CI, 1.22-1.26; P =8×10^-26) and duplications (OR, 1.12; 95% CI, 1.11-1.13; P =3×10^-26) was observed for the ASD group compared with control individuals. No differences in CRSs were observed between the early onset psychosis and ASD cohorts.

In the sensitivity analyses, the subgroup of children with early onset psychosis excluding those with later symptom onset, had fewer recurrent CNVs than the ASD cohort (P =.02) and CRSs were significantly higher among the early onset psychosis subgroup when individuals with intellectual disability (P =.03) and schizophrenia (P =.02) were excluded.

The major limitation of this study was the small sample size of the early onset psychosis cohort.

“Given the high frequency of recurrent CNVs in the EOP [early onset psychosis] group and comparable CRSs in the EOP and ASD groups, the findings suggest that all children and adolescents with a psychotic diagnosis should undergo genetic screening, as is recommended in ASD,” the researchers concluded.

These data indicated that there may be a shared genetic burden among children with early onset psychosis and ASD, indicating that children presenting with early onset psychosis should likely undergo genetic screening for ASD.

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.