Comparing PCR With High-resolution Melting Analysis for Apolipoprotein E Genotyping in Alzheimer's: A Case-control Study

The apolipoprotein E (APOE) genotype has a heterogeneous distribution throughout the world. The present study aimed to characterize the APOE genotype (rs429358, rs7412) in healthy individuals compared with Alzheimer cases in Kerman, southeastern Iran, by two standard mutation scanning methods. 

In this case-control study, 90 Alzheimer patients as a case group and 90 healthy individuals as a control group were examined. APOE genotyping was carried out using high-resolution melting (HRM) analysis assay and multiplex tetra-primer amplification-refractory mutation system polymerase chain reaction (T-ARMS PCR) techniques.

In contrast to Multiplex T-ARMS PCR, HRM analysis was not efficient in rs7412 genotyping. The results of multiplex T-ARMS showed that ε2ε3 genotype (P=0.006, odd ratio [OR]=0.119) and ε2 allele (P=0.004, OR=0.129) were more prevalent in the control group compared with the case ones, whereas ε4 allele was associated with borderline risk of Alzheimer disease (P=0.099, OR=1.76). 

We concluded that Multiplex T-ARMS PCR could be considered as a better option than HRM analysis for APOE genotyping in terms of speed, accuracy, simplicity, and cheapness in large-scale use. Also, the present study revealed that ε2 ε3 genotype and ε2 allele are protective against Alzheimer whereas the ε4 allele cannot be strongly considered as Alzheimer genetic risk factor in Kerman, Iran. The results may help to choose a better technique for APOE genotyping.