An interstitial deletion of the long arm of chromosome 21 in a case of a first episode of psychosis


Jatinder Takhar Department of Psychiatry, University of Western Ontario, London Health Sciences Center, London, Ontario N6A 4G5, Canada


Objective: Case of an interstitial deletion of the long arm of chromosome 21 presenting with first episode of psychosis.

Method: A case report.

Results: A 16-year-high school student of Somalian origin presented with a first episode of psychosis, mild mental retardation and dysmorphic features. Chromosome analysis revealed an interstitial deletion in the long arm of chromosome 21, described as 46, XX del (21) (q21q22.1).

Conclusion: First episode of psychosis occurred in combination with neurobiological vulnerability and a complex genetic inheritance. The occurrence of psychosis in our case may be attributable to genes located within the region 21q21q22.1. The possibility that other loci exist on chromosome 21, which predispose to schizophrenia has to be considered. Identification of susceptibility genes will greatly facilitate investigation of factors that contribute to the disease process and may lead to early intervention and prevention.