Cui Y, et al. - Given that familial hypercholesterolemia (FH) constitutes a genetic cause of premature myocardial infarction (PMI), researchers examined a cohort of 225 Chinese patients with PMI to determine the prevalence of FH using genetic testing as well as to assess various diagnostic criteria. A relatively common prevalence of FH was reported. Ten patients had pathogenic mutations of low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin-kexin type 9 (PCSK9) and low-density lipoprotein receptor adaptor protein 1 (LDLRAP1) genes. Newly identified four mutations were LDLR c.129G>C, LDLR c.1867A>T, LDLRAP1 c.65G>C, and LDLRAP1 c.274G>A. By genetic testing, the estimated FH prevalence was 4.4%. By Dutch Lipid Clinic Network (DLCN) and modified DLCN criteria, the estimated prevalence of definite/probable FH reached 8.0% and 23.6%, respectively, and the mutation rates were 33.3% and 12.2%, respectively. FH is still underdiagnosed and undertreated, which in itself poses a huge problem.