Determination of apolipoprotein E genotypes by single-strand conformational polymorphism.

We used single-strand conformational polymorphism (SSCP) to determine apolipoprotein E (Apo E) genotypes in 47 individuals. A 295-base-pair (bp) DNA fragment coding for amino acid residues 80-178 of the Apo E protein gave distinct patterns for the three alleles. When we used SSCP to determine the Apo E polymorphism of five individuals whose phenotyping results differed from those of genotyping, the SSCP results agreed with the genotyping results obtained by the PCR-based amplification refractory mutation system (ARMS). Because most of the reported rare alleles of the Apo E gene involve mutations of amino acid residues in positions 120-160, our SSCP method is useful for determining rare as well as common alleles.