Apolipoprotein E (apoE) restriction isotyping used oligonucleotides to amplify apoE gene sequences containing amino acid positions 112 and 158. The amplification products were digested with HhaI and subjected to electrophoresis on $4\%$ agarose gel. Each of the isoforms was distinguished by a unique combination of HhaI fragment sizes that enabled unambiguous typing of all homozygotic and heterozygotic combinations. HhaI cleaves at GCGC encoding 112arg (E4) and 158arg (E3, E4), but does not cut at GTGC encoding 112cys (E2, E3) and] 58cys (E2). DNA was isolated from 72 study participants and apoE genotypes were determined utilizing the polymerase chain reaction and restriction isotyping. In the entire group of subjects, $38 (52.8\%)$ had apo E4/4 or E3/4 (Group E4), $28(38.9\%)$ had the apo E3/3 genotype (Group E3) and $6(8.3\%)$ had apo E2/2 or E2/3 (Group E2). This genotypic information may help to identify individuals at increased risk for several diseases.