Fig.2. Genetic diagnosis of a family with LDLR mutation .

The index patient was a 4-year-old boy that presented with xanthoma over both ankles since birth. Genetic testing showed three LDLR mutations detected by mass spectrometry. Based on the Sanger sequencing analysis of DNA collected from his family, the LDLR c.1322 T＞C (p.A431T)＋LDLR c.1867 A＞G (p.I623V) are in one allele and LDLR c.1747 C＞T (p.H583Y) is in the other allele. CVD, cardiovascular disease; HDL-C, high-density lipoprotein-cholesterol; LDL-C, low-density lipoprotein-cholesterol; TC, total cholesterol; TG, triglyceride.