Chromosome 22q11.2 deletion syndrome and genetic variations including single-nucleotide polymorphism (SNP) and copy number variation (CNV) in catechol-O-methyltransferase (COMT) situated at 22q11.2 remains controversial. Here, the genetic relationship between COMT and Japanese patients with schizophrenia was investigated by examining whether the SNPs correlated with schizophrenia based on a common disease-common variant hypothesis. Additionally, 22q11.2DS were screened based on a common disease-rare variant hypothesis; low-frequency CNVs situated at two COMT promoters and exons were investigated based on the low-frequency variants with an intermediate effect; and positive findings from the first stage were reconfirmed using a second-stage replication study including a larger sample size. Eight SNPs and 10 CNVs were investigated using Taqman SNP and CNV quantitative real-time polymerase chain reaction method. For the first-stage analysis, 513 unrelated Japanese patients with schizophrenia and 705 healthy controls were examined. For the second-stage replication study, positive findings from the first stage were further investigated using a larger sample size, namely 1,854 patients with schizophrenia and 2,137 controls. The first-stage analysis showed significant associations among schizophrenia, intronic SNP rs165774, CNV6 situated at promoter 1, CNV8 at exon 6, and CNV9 at exon 7. The second-stage study showed that intronic SNP rs165774 (χ2=8.327, P=0.0039), CNV6 (χ2=19.66, P=0.00005), and CNV8 (χ2=16.57, P=0.00025) were significantly associated with schizophrenia. Large and rare CNVs as well as low-frequency CNVs and relatively small CNVs, namely <30kb in COMT, may be genetic risk factors for schizophrenia.
|Number of pages||11|
|Journal||American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics|
|Publication status||Published - 01-04-2016|
All Science Journal Classification (ASJC) codes
- Psychiatry and Mental health
- Cellular and Molecular Neuroscience