Schizophrenia is a highly heritable disorder. Around 30 schizophrenia-associated loci have been identified through GWAS (genome-wide association study). Schizophrenia Working Group of the Psychiatric Genomics Consortium (PGC) was set up to study genetic factors using larger samples. The group combined all available schizophrenia samples with published or unpublished GWAS genotypes into a single, systematic analysis and the results are now published.
The analysis included 49 ancestry matched, non-overlapping case-control samples ( 34,241 cases and 45,604 controls) and 3 family-based samples.
108 loci were identified , 83 of this were not previously identified. 75% of this include protein-coding genes . This include DRD2 (the target of all effective antipsychotic drugs) and many genes involved in glutamatergic neurotransmission and synaptic plasticity. Genes that encode voltage-gated calcium channel subunits are also involved.
Other interesting findings include:
1.Copy Number Variants associated with schizophrenia overlap with those associated with autism spectrum disorder and intellectual disability.
2.Schizophrenia associations were more relevantly shown in tissues with important immune functions.
This is the largest molecular genetic study of any neuropsychiatric disorder, ever conducted and it has produced exciting converging evidence that will soon illuminate the biology of schizophrenia and may be more effective treatments in due course.
Summary of the article:
Biological insights from 108 schizophrenia-associated genetic loci. Schizophrenia Working Group of the Psychiatric Genomics Consortium. NATURE | VOL 511 | JULY 2014.