Familial hypercholesterolemia (FH) is a common inherited disease that exhibits significantly increased levels of low-density lipoprotein cholesterol (LDL-C), skin or tendon xanthomas, corneal arcus and premature coronary heart disease (CHD). The prevalence of heterozygous FH is nearly 1/300 worldwide, and the prevalence of homozygous FH (HoFH) is 1/160,000 - 1/300,000. The Dutch Lipid Clinic Network diagnostic (DLCN) criteria is the most commonly recommended criteria for diagnosing FH patients. However, another disease with a similar clinical phenotype to FH must be differentiated from FH. This disease is a rare autosomal recessive disorder, sitosterolemia, and its incidence rate is approximately 1/5 million. We report a 16-month-old child with suspected HoFH and LDL-C levels that were reduced from 14.69 mmol/L to 3.24 mmol/L after dietary control without statin therapy. Gas chromatography detection of plant sterol levels and targeted exon sequencing chips for genetic testing were used to reach confirmed the diagnosis of sitosterolemia. (C) 2017 National Lipid Association. All rights reserved.