Mutation analysis of DARPP-32 as a candidate gene for schizophrenia

CH Li, HM Liao, TW Hung, CH Chen - Schizophrenia research, 2006 - Elsevier
CH Li, HM Liao, TW Hung, CH Chen
Schizophrenia research, 2006Elsevier
Dopamine-and cAMP-regulated phosphoprotein of relative molecular mass 32kDa (DARPP-
32) plays a pivotal role in the signal transduction of several neurotransmitters and
neuromodulators that are implicated in the pathophysiology of a variety of neuropsychiatric
disorders. A postmortem study reported a significantly reduced DARPP-32 expression in the
dorsolateral prefrontal cortex (DLPFC) of patients with schizophrenia, suggesting possible
involvement of DARPP-32 in the pathophysiology of schizophrenia. Hence, DARPP-32 was …
Dopamine- and cAMP-regulated phosphoprotein of relative molecular mass 32kDa (DARPP-32) plays a pivotal role in the signal transduction of several neurotransmitters and neuromodulators that are implicated in the pathophysiology of a variety of neuropsychiatric disorders. A postmortem study reported a significantly reduced DARPP-32 expression in the dorsolateral prefrontal cortex (DLPFC) of patients with schizophrenia, suggesting possible involvement of DARPP-32 in the pathophysiology of schizophrenia. Hence, DARPP-32 was considered as a candidate gene for schizophrenia in this study. We first systemically searched for mutations in the DARPP-32 gene in 50 Han Chinese patients with schizophrenia from Taiwan. Five molecular variants were identified, including a C-to-G substitution (g.-2036C>G) in the putative core promoter that obliterated a predictive AP-2 transcription factor binding site, a G deletion in the untranslated exon 2 (g.1238delG), a G-to-A and an A-to-G substitutions in intron 2 (IVS2+31G>A) and intron 6 (IVS6+32A>G), respectively, and a three-base pair deletion of AGA in exon 6 that resulted in deletion of a glutamate at codon 135 (E135del). Further SNP- and haplotype-based association study in 249 patients and 273 control subjects, however, did not detect association of these markers with schizophrenia. Hence, our results suggest that the reduced DARPP-32 protein in patients with schizophrenia is unlikely caused by mutations in the DARPP-32 gene itself and the DARPP-32 gene is also unlikely a major susceptibility gene for schizophrenia. Nevertheless, the identification of these molecular variants should help the study of gene regulation and structure–function relationship of DARPP-32, and the association study of DARPP-32 gene with other neuropsychiatric disorders.
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