Familial hypercholesterolemia (FH) is a genetic disorder that may lead to premature coronary heart disease (CHD) and sudden cardiac death (SCD). Mutations in the LDLR or APOB genes cause FH. We have screened the LDLR and the ligand-binding region of APOB genes in 52 cases of SCD. Deceased patients were younger than 40 years of age and were suspected of having FH. The LDLR and APOB genes were examined via PCR, high-resolution melting, and DNA sequencing. Therein, it was observed that 7.7% of the screened patients exhibited a rare sequence variant in the LDLR gene, with 5.7% suspected of being pathogenic mutations. Lipid profiles and genetic testing for FH could be considered when autopsy reveals significant atherosclerosis of the coronary arteries in young adults. First-degree family members are advised to seek medical advice and testing to determine their own risks of atherosclerosis to prevent premature CHD and SCD.