Abstract: “Familial defective Apolipoprotein B-100 (Apo B-100) was caused by the R3500Q mutation of the Apo B gene resulting in a glutamine substitution for the arginine residue, consequently, decreased binding of LDL to the LDL receptor. In current study, a total of 40 blood samples were collected from hyperlipidemia, which were confirmed by the concentration of cholesterol over 5.2 mmol/L. AS PCR (allele specific PCR) was carried to analyze the R3500Q mutation, then, confirmed by PCR sequencing. As the results, 27 of 40 (counting for 67.50%) cases were identified being R3500Q mutation. In which, the prevalence of heterozygote and homozygous in this selected population was 25 of 27 (counting for 92.59%), and 2 of 27 (counting for 7.41%), respectively. By PCR sequencing, results were totally according to results of AS PCR analyzation. Giving clearly evidence, two peaks were observed corresponding to two alleles, one allele sequence is G and another is A, that concluded as heterozygote (G→A transi”

Keywords: ApoB, ApoB-100, familial hypercholesterolemia, haplotype R3500Q, Vietnamese population