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Journal of the neurological sciences 10/2010; · 2.32 Impact Factor
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ABSTRACT: Alzheimer's disease (AD) is characterized by the presence of beta-amyloid plaques, neurofibrillary tangles and extensive neuronal loss. There is evidence indicating that the increased DNA damages may contribute to neuronal loss in AD. Recently, it has been shown that the capacity of some types of DNA repair is impaired in the neurons of AD patients. A functional polymorphism (Arg194Trp) of X-ray repair cross-complementing group 1 (XRCC1) gene may be associated with the repair efficiency of DNA damage which may have a role in AD. Therefore, XRCC1 Arg194Trp polymorphism may be a good candidate for genetic risk analysis in AD. A case-control study from Turkey found that XRCC1 194Trp was associated with late-onset AD (LOAD). In order to determine whether the XRCC1 gene Arg194Trp polymorphism contributes to the risk for LOAD in elderly Han Chinese, we have investigated it in 212 sporadic LOAD patients and 203 healthy controls from Chinese. No significantly increased risk of LOAD in the carriers of XRCC1 194Trp allele (OR=1.04, 95% CI 0.70-1.52, P=0.860) was observed. As expected, Apolipoprotein (APOE) epsilon4 allele significantly increased the risk of LOAD (OR=2.95, 95% CI 1.90-4.58, P<0.001), while APOE epsilon2 allele significantly decreased the risk of LOAD (OR=0.13, 95% CI 0.08-0.24, P<0.001). After stratifying by APOE epsilon4 status, no increased LOAD risks associated with the XRCC1 194Trp allele carriers were observed. Our findings suggest that it is unlikely that the XRCC1 Arg194Trp polymorphism plays a major role in the pathogenesis of LOAD in elderly Han Chinese and does not support the previous findings that 194Trp allele confers an increased risk for LOAD.
Journal of the neurological sciences 08/2010; 295(1-2):62-5. · 2.32 Impact Factor
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ABSTRACT: The Catechol-O-methyltransferase (COMT) plays an important role in the development of breast cancer. Many previous epidemiologic studies explored the association of COMT Val158Met polymorphism with breast cancer susceptibility. However, the results were inconsistent. We therefore performed a meta-analysis of 26 published studies including 16,693 breast cancer patients and 18,261 healthy controls. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association of the COMT Val158Met polymorphism with breast cancer risk. No significant association was found in all genetic models in overall, Asian, European populations. After the studies whose genotype frequencies in the controls did not fulfill Hardy-Weinberg equilibrium were excluded, we found a borderline significant decreased breast cancer risk among Europeans (for the recessive model LL versus HH/HL: OR = 0.90, 95% CI = 0.90-1.00, P (heterogeneity) = 0.33). There was no between-study heterogeneity. In conclusion, COMT Val158Met polymorphism may be a low-penetrant risk factor for breast cancer development in European population.
Breast Cancer Research and Treatment 08/2010; 123(1):265-70. · 4.43 Impact Factor
