How proteomic ApoE serotyping could impact Alzheimer's disease risk assessment: genetic testing by proteomics

Humans have three major apolipoprotein E (ApoE) alleles (APOE; ε2, ε3 and ε4) that produce three ApoE protein isoforms. The ε2 allele encodes the ApoE2 isoform (Cys112, Cys158), whereas ε3 encodes the wild-type ApoE3 isoform (Cys112, Arg158) and ε4 encodes the ApoE4 isoform (Arg112, Arg158). Because the type of ApoE expressed is related to sporadic Alzheimer's disease risk and familial hyperlipidemia, many clinical studies have utilized ApoE typing in recent years. ApoE serotyping is based on the correlation between ApoE genotype and isoform; it is therefore possible to determine the genotype from the blood ApoE isoform combination. Serotyping ApoE using mass spectrometry promises highly accurate results while requiring minimal amounts of blood and reagents, resulting in lower costs, which suggest that proteomic-based ApoE serotyping may eventually become a routine clinical laboratory test. Not limited to ApoE, proteomic analysis of human samples could be used to intentionally determine - and perhaps unintentionally reveal - personal genetic information.