Latest findings in the genetic architecture of schizophrenia: The contribution of genetic studies among Afrikaners

Abstract

A genetic component of schizophrenia has been acknowledged for a long time. The underlying architecture of the genetic risk remains a contentious issue. Early linkage and candidate association studies led to largely inconclusive results. More recently powerful technologies became available. This aspect coupled with samples of sufficient sizes, and genome-wide panels of genetic markers facilitated systematic and agnostic scans throughout the genome for either common or rare disease risk variants of small or large effect size, respectively. Although the former had limited success, the role of rare genetic events, such as copy-number variants (CNVs) or rare point mutations, has become increasingly important in gene discovery for schizophrenia. Recent research done among Afrikaner patients with schizophrenia, building upon earlier findings of de novo recurrent CNVs at the 22q11.2 locus, has highlighted a de novo mutational paradigm as a major component of the genetic architecture of schizophrenia. Recent progress in this regard will be reviewed.