BACKGROUND: Apolipoprotein E (ApoE) plays a role in the regulation of lipid 
metabolism in humans. ApoE, a 229-amino-acid polypeptide, is classified into 
three major isoforms (E2, E3, and E4) according to the differences in amino 
acids at positions 112 and 158. In the normal population, ApoE3 isoform is the 
most prevalent, and ApoE2 or E4 is frequently associated with 
hyperlipoproteinemia. The objective of this work was to investigate the 
relationship between ApoE gene polymorphism and coronary heart disease (CHD) in 
Gaza Strip and investigate the association between serum lipid levels and CHD.
MATERIAL AND METHODS: The study population consisted of 137 subjects including 
69 CHD cases (45 male, 24 female) and 68 healthy subjects (33 male and 35 
female).
RESULTS: The ApoE3/E3 genotype was the most common in the control and the CHD 
groups. ApoE2/E3 and ApoE3/E4 were the next most common genotypes. The 
frequencies of ApoE alleles in the CHD subjects were 0.826 for E3, 0.137 for E4, 
and 0.0362 for E2. These frequencies are comparable to those found in the 
control group which were 0.875 for the E3, 0.073 for E4, and 0.0515 for E2. No 
statistically significant differences in ApoE genotypes were found between the 
patients and the control groups. Moreover, there was no significant difference 
between the mean of triglyceride (TG) and HDL levels among different ApoE 
genotypes. However, there was a significant difference in the mean of LDL and 
ApoE genotypes where the mean of LDL was 218.17 mg/dl in ApoE4, 149.67 mg/dl in 
ApoE2, and 184.52 mg/dl in ApoE3. A significant difference was also evident 
between the mean of LDL levels in the CHD and the control group where the mean 
of LDL was 126 mg/dl in CHD and 111.47 mg/dl in the control group. Our study 
indicated that there was no significant difference between the mean of 
cholesterol and TG levels of the CHD and the control groups.
CONCLUSIONS: To our knowledge, this is the first study in Gaza Strip 
investigating the relation between ApoE genotypes and CHD. Further 
investigations are needed to link other genetic factors to CHD.