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A total of 202 Sardinian male subjects were examined for 13 biallelic stable markers, the complex 49a,f/TaqI system and three microsatellites of the Y chromosome in order to investigate, through surname analysis, on a possible territorial heterogeneity inside the island. The study of geographical distribution and linguistic derivation of Sardinian surnames allow us to discover their ‘probable place of origin’ and reconstruct ancient genetic isolates which borders are, today, no more recognizable. The molecular analysis revealed that about 90% of the Sardinian Y chromosomes fell into haplogroups E-M35, G-M201, I-M26, J-12f2 and R-M269. In contrast with the territorial homogeneity of these haplogroups, when the individuals were distributed according to their birthplace, a significant difference between the three historically and culturally distinct geographical areas into which Sardinia can be subdivided was observed when the individuals were distributed according to the ancestral location of surnames. In particular, the major contribution to this heterogeneity is due to the ‘Sardinian-specific’ haplogroup I-M26 (almost completely associated with the 49a,f-Ht12/12f2-10Kb/YCAIIa-21/YCAIIb-11 compound haplotype), which shows both a significantly higher incidence in the central-eastern (archaic) area and a significantly lower frequency in the northern area. The results of this study agree with the hypothesis that the ancestral homeland of this specific subset of haplogroup I is the mountainous central-eastern area of Sardinia, where the population underwent a long history of isolation since ancient times, and highlight the informative power of the surname analysis.European Journal of Human Genetics (2003) 11, 802-807. doi:10.1038/sj.ejhg.5201040 [ABSTRACT FROM AUTHOR]

A 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., ((c) 2007 Wiley-Liss, Inc.)