ApoE polymorphisms in narcolepsy.
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ABSTRACT:
SUBMITTER: Gencik M
PROVIDER: S-EPMC55694 | biostudies-other | 2001
REPOSITORIES: biostudies-other
Publications
ApoE polymorphisms in narcolepsy.
Gencik M M Dahmen N N Wieczorek S S Kasten M M Gencikova A A Epplen J T JT
BMC medical genetics 20010809
<h4>Background</h4>Narcolepsy is a common neuropsychiatric disorder characterized by increased daytime sleepiness, cataplexy and hypnagogic hallucinations. Deficiency of the hypocretin neurotransmitter system was shown to be involved in the pathogenesis of narcolepsy in animals and men. There are several hints that neurodegeneration of hypocretin producing neurons in the hypothalamus is the pathological correlate of narcolepsy. The ApoE4 allele is a major contributing factor to early-onset neuro ...[more]
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Project description:PurposeAPOLIPOPROTEIN E (APOE, MIM: 107741) has three functionally distinct isoforms of the protein (E2, E3, and E4), encoded by corresponding alleles ε2, ε3, and ε4, which have been well described. Findings from previous studies investigating association between APOE polymorphisms and breast cancer risk have been inconsistent. The present meta-analysis was conducted in order to investigate association of APOE polymorphisms with risk of breast cancer.Materials and methodsSeveral electronic databases were used for identification of studies containing information on APOE polymorphisms and breast cancer risk published up to January 2012. We identified 10 eligible studies, including 3,835 subjects (2008 patients, and 1,827 healthy controls), that reported on polymorphisms of APOE and risk of breast cancer. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were obtained using a fixed and random-effects models.ResultsAmong studies reported from Asia, an association of the ε4 allele with increased risk of breast cancer, in comparison with the ε3 allele, was observed (OR, 1.56; 95% CI, 1.19 to 2.04; p=0.001). It should be noted that allele ε2 showed no association with breast cancer risk. Among Caucasians, neither the ε4 (OR, 0.99; 95% CI, 0.83 to 1.17; p=0.917) nor the ε2 (OR, 0.92; 95% CI, 0.72 to 1.17; p=0.514) allele showed an association with susceptibility to breast cancer, when compared with the ε3 allele. Carriers of the ε4 allele (E4E4, E4E3, and E4E2 genotypes), in comparison with the E3E3 genotype, showed an association with elevated risk of breast cancer only among Asians (OR, 1.75; 95% CI, 1.23 to 2.47; p=0.002). No publication bias was detected.ConclusionThis meta-analysis suggest that the APOEε4 allele is a low-penetrant risk factor for development of breast cancer.
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Project description:BACKGROUND Apolipoprotein E (ApoE) is a multifunctional protein that plays an important role in lipoprotein metabolism. However, the relationship between APOE gene polymorphisms and cerebral infarction in the Chinese population remains unclear. Therefore, we studied the role of APOE gene polymorphisms in patients with cerebral infarction in a Chinese population. MATERIAL AND METHODS This study involved 906 patients with cerebral infarction and 1,141 individuals without cerebral infarction who served as controls. APOE genotypes were identified in all participants who participated in the study. Factors influencing cerebral infarction were also analyzed. RESULTS Statistically significant variances in the distribution and frequencies of the APOE genotypes in the patients were observed (ε2/ε3 versus ε2/ε4 versus ε3/ε3=22.85% versus 7.62% versus 56.95%) and controls (ε2/ε3 versus ε2/ε4 versus ε3/ε3=17.27% versus 2.72% versus 66.87%; p<0.001). Univariate analysis showed that the APOE ε3/ε3 genotype [OR, 0.393 (95% CI, 0.237-0.653); p<0.001] and ε3/ε4 genotype [OR, 0.376 (95% CI 0.221-0.637); p<0.001] played a protective role against cerebral infarction in Chinese men. CONCLUSIONS Statistically significant variances in the distribution and frequencies of the APOE genotypes of the patients and controls were observed. The study demonstrated that the APOE ε3/ε3 and ε3/ε4 genotypes played a protective role against cerebral infarction in Chinese men, but not women. Additionally, the ε2/ε4 genotype may be a potential risk factor in men, whereas ε3/ε4 genotype may play a potential protective role against this disease in women.
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