Chromosome 22q11 in a Xhosa schizophrenia population.

Chromosome 22q11 aberrations substantially increase the risk for developing schizophrenia. Although micro-deletions in this region have been extensively investigated in different populations across the world, little is known of their prevalence in African subjects with schizophrenia. We screened 110 African Xhosa-speaking participants with schizophrenia for the presence of micro-deletions. As further verification for the presence or absence of 22q11 microdeletions, we screened 238 Xhosa schizophrenia patients and 240 healthy Xhosa individuals from a larger schizophrenia candidate 22q11 gene study using molecular analyses. Data from molecular and cytogenetic analyses confirmed the absence of 22q11 microdeletions in the Xhosa schizophrenia samples. Although the absence of chromosome 22q11 micro-deletions in this group of patients does not exclude the possibility that it may occur in Xhosa schizophrenia patients, we concluded an extremely low prevalence. Our findings suggest that unique susceptibility loci may be present in this group.