The new genetics of schizophrenia.
Despite the genetic and phenotypic complexity of schizophrenia, much progress has been made. Research has largely excluded the possibility that genes of major effect exist; linkage analysis has provided independently replicated evidence for genes of moderate effect on several chromosomal regions. Association studies suggest that alleles of at least two genes, those encoding D3 and 5HT2A, confer a small rise in susceptibility to schizophrenia, and there are convergent findings from several different lines of research implicating regions such as 22q11, although no specific causative genes for schizophrenia have been definitively identified yet. There are strong grounds for optimism as larger samples are collected to increase the power of studies, and novel methods of statistical analysis and large-scale genotyping of SNPs are developed and refined. Although the difficulties and challenges of genetics research into schizophrenia are formidable, the devastating personal and social consequences of the illness make it imperative that these challenges are faced, because the identification of susceptibility genes for schizophrenia would result in further productive neurobiologic research and ultimately improvements in the prevention and treatment of schizophrenia.
McDonald
Colm
C
Division of Psychological Medicine, Institute of Psychiatry, de Crespigny Park, London SE5 8AF, United Kingdom. c.mcdonald@iop.kcl.ac.uk
Murphy
Kieran C
KC
D000300:Adoption; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D017353:Gene Deletion; D005817:Genetic Counseling; D008040:Genetic Linkage; D006801:Humans; D010641:Phenotype; D012307:Risk Factors; D012559:Schizophrenia / Q000235:genetics*; D018433:Twin Studies as Topic