Alzheimer's Disease In Korean Population Research Articles

Polymorphisms of small ubiquitin-related modifier genes are associated with risk of Alzheimer's disease in Korean: A case-control study

Sumoylation regulates transcription factor transactivation, protein-protein interactions, and appropriate subcellular localization of certain proteins. Previous studies have shown that sumoylation of amyloid precursor protein (APP) is associated with decreased levels of amyloid beta (Aβ) proteins, suggesting that sumoylation may play a role in the pathogenesis of Alzheimer's disease (AD). We investigated the association between polymorphisms of the SUMO genes and the risk of AD. Our study subjects consisted of 144 AD patients and 335 healthy controls without dementia. We focused on tagged single nucleotide polymorphisms (tagSNPs) of the SUMO1 and SUMO2 genes. The tagSNPs were amplified by PCR and sequenced. We used binary logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for the associations between SUMO gene polymorphisms and the risk of AD. We found that rs12472035 polymorphism of SUMO1 was significantly associated with an increased risk of AD in male group (the CT genotype of rs12472035: adjusted OR=8.737, 95% CI=2.041–37.41, p-value=0.003). In addition, two polymorphisms of SUMO2 were significantly associated with an increased risk of AD in female group (the GA genotype of rs35271045: adjusted OR=2.879, 95% CI=1.399–5.924, p-value=0.004; and the TC genotype of rs9913676: adjusted OR=2.460, 95% CI=1.197–5.057, p-value=0.014). Furthermore, three combinations were associated with an increased risk of AD. Our data suggest that three individual polymorphisms and three combinations may be potential risk factors for AD in Korean population.

Association of GWAS Top Hits With Late-onset Alzheimer Disease in Korean Population

Recent genome-wide association studies (GWAS) have discovered several Alzheimer disease (AD) susceptibility loci. However, the identified susceptibility loci are substantially inconsistent across GWAS. We aimed to investigate the association of top associated variants in GWAS with AD in Korean population. We selected 86 single-nucleotide polymorphisms (SNPs) selected from 12 genes (ABCA7, APOE, BIN1, CD2AP, CD33, CLU, CR1, EPHA1, LRAT, MS4A6A, PCDH11X, and PICALM) and genotyped in 290 AD cases and 554 unrelated controls from the same region. Three SNPs [rs429358 in APOE: odds ratio (OR)=4.24, 95% confidence interval (CI)=3.01-5.96, P=1.23×10; rs2075650 in APOE: OR=3.57, 95% CI=2.51-5.06, P=1.23×10; and rs677909 in PICALM: OR=0.63, 95% CI=0.49-0.81, P=0.00036, log additive model] were significantly associated with AD susceptibility after correction for multiple testing. Six additional PICALM SNPs, 3 ABCA7 SNPs, and 1 APOE, CD33, and BIN1 SNPs each had significant uncorrected P values. There was no significant association for age at onset of AD. Our results confirm the association of PICALM gene (encoding phosphatidylinositol-binding protein) in addition to APOE gene with AD susceptibility in Korean population but did not show significant associations of other susceptibility loci with AD.

No association of prion protein gene polymorphisms with Alzheimer's disease in Korean population

The polymorphism at codon 129 (M129V) of the human prion protein gene (PRNP) is a known risk factor for Creutzfeldt-Jakob disease (CJD) in Caucasians. There are few reports of this polymorphism's effect on memory and on the risk of Alzheimer's disease (AD). The M129V genotype distributions among Asians are very different from Caucasians. Another polymorphism, codon 219 (E219K) is not found in Caucasians. We investigated two polymorphisms of PRNP, M129V (rs1799990) and E219K (rs1800014) in 297 Korean AD patients and 217 healthy subjects. The analysis of the genotype and allele distributions showed no significant difference between the AD patients and the controls in both polymorphisms (P=0.19 genotype, P=0.51 allele for M129V; P=0.64 genotype, P=0.50 allele for E219K). Also, the PRNP polymorphisms were not significantly associated with AD when the populations were stratified for the presence or absence of apolipoprotein E-epsilon4 (ApoE-epsilon4) allele. These results suggest that the PRNP genetic variants are not associated with the risk for AD in Korean population.

ApoE-ε 4-dependent association of the choline acetyltransferase gene polymorphisms (2384G>A and 1882G>A) with Alzheimer's disease

Background One of the characteristic features of Alzheimer's disease (AD) is the degeneration of the cholinergic system. The gene encoding choline acetyltransferase (ChAT), a key enzyme in cholinergic function, is a candidate gene conferring risk for AD. But the genetic association of the enzyme with AD has been controversial. We analyzed 2 ChAT single nucleotide polymorphisms (SNPs), 2384G>A (rs3810950; Ala120Thr) and 1882G>A (rs1880676; Asp7Asn) and the ApoE polymorphisms in Korean population. Methods The samples from 316 AD patients and 264 age-matched healthy controls were analyzed. The differences in genotype frequencies were assessed. Results The 2 ChAT SNPs were almost completely linked with each other ( r 2 = 0.99, | D′| = 1.0). No significant difference in the ChAT genotype distribution was observed between the patients and the controls. However, in non-ApoE-ε4 allele carriers, multiple logistic regression analysis showed that both the GA and the GA/AA genotypes were associated with AD (OR = 1.639, 95% CI, 1.050–2.559, p = 0.0297 for GA; OR = 1.630, 95% CI, 1.049–2.532, p = 0.0297 for GA/AA), suggesting a dominant effect of A allele. Conclusion There is considerable effect of the ChAT polymorphisms on AD in Korean population and this effect is dependent on ApoE genotypes.