CYP46A1 T/C polymorphism associated with the APOE ε4 allele increases the risk of Alzheimer's disease.
Studies of the relationship between Alzheimer's disease (AD) and single nucleotide polymorphism (SNP) T/C in intron 2 of the cholesterol-24S-hydroxylase gene (CYP46A1) have reported inconsistent results. To confirm the association between the CYP46A1 T/C polymorphism and AD risk, a meta-analysis containing 4,875 AD cases and 4,874 controls from 21 case-control studies was performed. There were 16 studies involving Europeans, four studies with Asians and one study with Africans. The combined results of overall analysis showed that the CYP46A1 T/C polymorphism increased the risk of AD significantly in recessive model [CC versus CT + TT, odds ratio (OR) = 1.20, 95 % confidence interval (CI) = 1.04-1.38, p = 0.01]. On subgroup analysis by ethnicity, similarly significant differences in recessive model were also found in Europeans. Another analysis of the synergistic effect of the CYP46A1 T/C polymorphism and the ε4 allele of the apolipoprotein E gene (APOE ε4) was performed in eight studies with available stratified information. The results revealed that the presence of APOE ε4 allele could strengthen the effect of CC genotype on AD risk, and the reverse was also true. In conclusion, our meta-analysis has successfully proved that CC genotype of the CYP46A1 T/C polymorphism could increase the risk of AD, and this effect would be weakened in APOE ε4 non-carriers and strengthened in APOE ε4 carriers.
Department of Neurology and Center for Clinical Neuroscience, Daping Hospital, Third Military Medical University, No. 10 Changjiang Branch Road, Daping, Chongqing 400042, China.
Ling
L
Li
Zegang
Z
Yin
Juan
J
Liu
Gongbo
G
Li
Yanjiang
Y
Wang
Jiachuan
J
Yan
Huadong
H
Zhou
D000483:Alleles; D000544:Alzheimer Disease / Q000235:genetics*; D053327:Apolipoprotein E4 / Q000235:genetics*; D000072556:Cholesterol 24-Hydroxylase; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D013250:Steroid Hydroxylases / Q000235:genetics*
D053327:Apolipoprotein E4; D013250:Steroid Hydroxylases; D000072556:Cholesterol 24-Hydroxylase