A case of sitosterolemia misdiagnosed as familial hypercholesterolemia: A 4-year follow-up.

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.