Amplification refractory mutation system polymerase chain reaction versus optimized polymerase chain reaction restriction-fragment length polymorphism for apolipoprotein e genotyping of majorly depressed patients

Abstract

Major depressive disorder (MDD) is a prevalent, debilitating mood disorder that has been associated with several genetic polymorphisms. One such polymorphism, namely that of apolipoprotein E (APOE), has three allelic forms (ε2, ε3 and ε4) that encode for six unique isoforms of the APOE protein. A growing number of techniques have been developed for APOE genotyping; however, not all polymerase chain reaction (PCR)-based genotyping techniques are equally accurate or cost-effective. In order to find a more accurate and cost-effective APOE genotyping method for MDD screening in large populations, the present study comparatively evaluated two genotyping methods, amplification refractory mutation system PCR (ARMS-PCR) and optimized PCR restriction-fragment length polymorphism (PCR-RFLP), in blood samples taken from a population of 708 MDD patients. Although either of the two methods were able to detect all six unique APOE genotypes, comparisons of the two methods with Sanger sequencing demonstrated that ARMS-PCR (94%) was significantly more accurate than optimized PCR-RFLP (82%). ARMS-PCR should prove useful in quickly verifying ambiguous results obtained by other APOE genotyping methods and can be cost-effectively performed in the setting of a small laboratory or a population-based screening program.