Genetic variation in the 22q11 locus and susceptibility to schizophrenia.
An increased prevalence of microdeletions at the 22q11 locus has been reported in samples of patients with schizophrenia. 22q11 microdeletions represent the highest known genetic risk factor for the development of schizophrenia, second only to that of the monozygotic cotwin of an affected individual or the offspring of two schizophrenic parents. It is therefore clear that a schizophrenia susceptibility locus maps to chromosome 22q11. In light of evidence for suggestive linkage for schizophrenia in this region, we hypothesized that, whereas deletions of chromosome 22q11 may account for only a small proportion of schizophrenia cases in the general population (up to approximately 2%), nondeletion variants of individual genes within the 22q11 region may make a larger contribution to susceptibility to schizophrenia in the wider population. By studying a dense collection of markers (average one single nucleotide polymorphism20 kb over 1.5 Mb) in the vicinity of the 22q11 locus, in both family- and population-based samples, we present here results consistent with this assumption. Moreover, our results are consistent with contribution from more than one gene to the strikingly increased disease risk associated with this locus. Finer-scale haplotype mapping has identified two subregions within the 1.5-Mb locus that are likely to harbor candidate schizophrenia susceptibility genes.
Liu
Hui
H
The Rockefeller University, Human Neurogenetics Laboratory, New York, NY 10021 USA.
Abecasis
Goncalo R
GR
Heath
Simon C
SC
Knowles
Alyson
A
Demars
Sandra
S
Chen
Ying-Jiun
YJ
Roos
J Louw
JL
Rapoport
Judith L
JL
Gogos
Joseph A
JA
Karayiorgou
Maria
M
D000595:Amino Acid Sequence; D002874:Chromosome Mapping; D002892:Chromosomes, Human, Pair 22; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D014644:Genetic Variation; D006801:Humans; D015810:Linkage Disequilibrium; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide; D012559:Schizophrenia / Q000235:genetics*