Antipsychotic Use Among Intellectually Disabled Individuals With Rare Genetic Variants That Confer Risk for...

Rare genetic variation can predispose individuals to the development of schizophrenia, with certain genes and copy number variants (CNVs) conferring risk at the exome/genome-wide level. Despite this strong association, little is known about antipsychotic effectiveness and tolerability among individuals with most of these disorders. As such, this retrospective chart review sought to gather more data regarding the real-world use of antipsychotics in this context.

This largely descriptive, cross-sectional and retrospective chart review took place at a developmental disabilities mental health clinic. Clinical information was primarily derived from electronic medical records. Individuals with a history of psychosis and antipsychotic exposure identified as having a genetic variant known to confer exome/genome-wide risk for schizophrenia were included in the study.

Of the 1196 charts reviewed, 24 individuals with a relevant genetic variant were identified, 11 of whom had experienced psychotic symptoms that were treated with antipsychotic medication. Six have 22q11.2 deletion syndrome, two have 15q11-q13 duplication syndrome and one individual each has a 16p11.2 duplication, a 7q11.23 duplication and a missense variant in TRIO. Overall, antipsychotic therapy tended to be reasonably effective and well tolerated (particularly among those individuals who do not have 22q11.2 deletion syndrome), despite side effects of some kind occurring in most cases.

While this study had numerous limitations that prevent firm conclusions from being drawn, it provides preliminary evidence that antipsychotics may be relatively safe and effective in at least some of the genetic disorders most strongly associated with schizophrenia.