Cui Y, et al. - In 225 consecutive Chinese premature myocardial infarction (PMI) patients, the prevalence of familial hypercholesterolemia (FH) was determined using genetic testing, and different diagnostic criteria were also assessed. Researchers used Sanger sequencing to identify LDLR, APOB, PCSK9 and LDLRAP1 genes. They used the Dutch Lipid Clinic Network (DLCN) criteria and modified DLCN criteria, respectively, to diagnose FH. Among all PMI patients, 10 of 225 had pathogenic mutations of LDLR, APOB, PCSK9 and LDLRAP1 genes. The newly discovered mutations were LDLR c.129G>C, LDLR c.1867A>T, LDLRAP1 c.65G>C, LDLRAP1 c.274G>A. A relatively common prevalence of FH (4.4%) was seen among Chinese patients with PMI. Using DLCN and modified DLCN criteria, the observed prevalence of definite/probable FH reached 8.0% and 23.6%, respectively, and the mutation rates were 33.3% and 12.2%, respectively. PMI patients with FH had low-density lipoprotein cholesterol (LDL-C) levels, which were far from goal attainment. LDL-C <2.5 mmol/L was detected in only one of the FH patients, and LDL-C <1.8 mmol/L was present in none. Overall, underdiagnosis and undertreatment of FH continued to be a big problem.