1Am. J. Med. Genet. B Neuropsychiatr. Genet. 2007 Jun 144B: 496-501
PMID17440949
TitleMitochondrial DNA haplogroups and age at onset of schizophrenia.
AbstractA number of studies support a possible link between mitochondrial dysfunction and schizophrenia. To test the hypothesis of a direct contribution of mitochondrial DNA (mt-DNA) in susceptibility to DSM-IV-TR-schizophrenia, we looked for differences in the frequency distribution of the major European haplogroups (HGS) in 142 patients and 190 controls both of Italian origin. A subgroup of patients (N = 37) and healthy counterparts (N = 41) was also analyzed for possible differences in the relative amount of mt-DNA versus nuclear-DNA in blood cells. Patients and controls were comparable for hg frequency distribution and the relative levels of mt-DNA even after stratification by gender and schizophrenia subtype. However, patients harboring the hg J-T showed an anticipated onset of the disorder. These results indicate that the J-T hg of mt-DNA may have a modulator effect on deeper determinants of schizophrenia.
SCZ Keywordsschizophrenia, schizophrenic
2Am. J. Med. Genet. B Neuropsychiatr. Genet. 2012 Jun 159B: 414-21
PMID22467472
TitleNo evidence that major mtDNA European haplogroups confer risk to schizophrenia.
AbstractPrevious studies suggest that genetic factors could be involved in mitochondrial dysfunction observed in schizophrenia (SZ), some of them claiming a role of mtDNA common variants (mtSNPs) and/or haplogroups (HGS) in developing this disorder. These studies, however, have mainly been undertaken on relatively small cohorts of patients and control individuals and most have not yet been replicated. To further analyze the role of mtSNPs in SZ risk, we have carried out the largest genotyping effort to date using two Spanish case-control samples comprising a total of 942 schizophrenic patients and 1,231 unrelated controls: 454 patients and 616 controls from Santiago de Compostela (Galicia) and 488 patients and 615 controls from Reus (Catalonia). A set of 25 mtSNPs representing main branches of the European mtDNA phylogeny were genotyped in the Galician cohort and a subset of 16 out of these 25 mtSNPs was genotyped in the Catalan cohort. These 16 common variants characterize the most common European branches of the mtDNA phylogeny. We did not observe any positive association of mtSNPs and HGS with SZ. We discuss several deficiencies of previous studies that might explain the false positive nature of previous findings, including the confounding effect of population sub-structure and deficient statistical methodologies. It is unlikely that mtSNPs defining the most common European mtDNA haplogroups are related to SZ.
SCZ Keywordsschizophrenia, schizophrenic
3Am. J. Med. Genet. B Neuropsychiatr. Genet. 2012 Jun 159B: 414-21
PMID22467472
TitleNo evidence that major mtDNA European haplogroups confer risk to schizophrenia.
AbstractPrevious studies suggest that genetic factors could be involved in mitochondrial dysfunction observed in schizophrenia (SZ), some of them claiming a role of mtDNA common variants (mtSNPs) and/or haplogroups (HGS) in developing this disorder. These studies, however, have mainly been undertaken on relatively small cohorts of patients and control individuals and most have not yet been replicated. To further analyze the role of mtSNPs in SZ risk, we have carried out the largest genotyping effort to date using two Spanish case-control samples comprising a total of 942 schizophrenic patients and 1,231 unrelated controls: 454 patients and 616 controls from Santiago de Compostela (Galicia) and 488 patients and 615 controls from Reus (Catalonia). A set of 25 mtSNPs representing main branches of the European mtDNA phylogeny were genotyped in the Galician cohort and a subset of 16 out of these 25 mtSNPs was genotyped in the Catalan cohort. These 16 common variants characterize the most common European branches of the mtDNA phylogeny. We did not observe any positive association of mtSNPs and HGS with SZ. We discuss several deficiencies of previous studies that might explain the false positive nature of previous findings, including the confounding effect of population sub-structure and deficient statistical methodologies. It is unlikely that mtSNPs defining the most common European mtDNA haplogroups are related to SZ.
SCZ Keywordsschizophrenia, schizophrenic