NEW YORK – A Boston Children's Hospital-led team has tracked down copy number variants (CNVs) with apparent ties to early-onset psychosis — psychotic symptoms such as hallucination that occur in children under 18 years old.
"Our findings make a strong case for chromosomal microarray testing in any child or adolescent diagnosed with psychosis," co-first and co-corresponding author Catherine Brownstein, a genetics and genomics researcher affiliated with Harvard Medical School, Boston Children's Hospital, and the BCH's Early Psychosis Investigation Center, and scientific director at BCH's Manton Center for Orphan Disease Research, said in a statement.
"We don't have medications tailored to CNVs yet," Brownstein added. "But when parents get together, they can organize and identify research devoted to their particular CNV. We can study their children as a group and identify effective treatments a lot faster."
As they reported in the American Journal of Psychiatry, the researchers used array-based profiling to search for risky CNVs in 137 children who were diagnosed with psychosis symptoms between the ages of 4 and 17 years old and referred to Boston Children's Hospital's Developmental Neuropsychiatry Program. Past studies have linked CNVs to neurodevelopmental conditions and to psychotic conditions that occur in older individuals.
When the team characterized CNV profiles in the children and adolescents with psychosis alongside CNV data for 5,540 autism spectrum disorder (ASD) cases and more than 16,500 unaffected control individuals, it uncovered suspicious duplications or deletions in some 40 percent of the individuals with early-onset psychosis.
"Overall, genetic screening in [early-onset psychosis] has the potential to bring us one step closer to true precision medicine in pediatric psychiatry," the authors wrote, adding that the risk alleles they detected "are also promising targets for biological research aimed at developing animal and cellular models to identify novel disease mechanisms and drug targets for psychotic disorders."
The CNV collection included almost four dozen recurrent CNVs implicated in psychiatric conditions or neurodevelopmental disorders such as ASD in prior studies, the team noted, although CNVs seemed to be far more prevalent in the early-onset psychosis cases than they were in either control individuals or individuals with ASD.
Even so, the investigators noted that such CNV burden differences were dialed down in individuals diagnosed with both early-onset psychosis and additional conditions such as ASD. More than one-quarter of the children met the criteria for schizophrenia diagnoses, they reported, while a significant subset of children had additional ASD, developmental disorder, intellectual disorder, and/or seizure-related diagnoses.
The team found that CNV risk scores (CRS) were comparable in individuals with early-onset psychosis or ASD, but far more muted in the unaffected control individuals.
"Given the high frequency of recurrent CNVs in the [early-onset psychosis] group and comparable CRSs in the [early-onset psychosis] and ASD group, the findings suggest that all children and adolescents with a psychotic diagnosis should undergo genetic screening, as is recommended in ASD," the authors wrote.