Familial hypercholesterolemia (FH) is also known as familial hyperbeta lipoproteinemia. Clinically characterized by hypercholesterolemia, characteristic yellow tumors, and a family history of early-onset cardiovascular disease, FH is the most common inherited hyperlipidemia in childhood and the most serious of the lipid metabolism disorders that can lead to the development of various life-threatening cardiovascular complications as a form of coronary artery disease. The most characteristic clinical manifestations of this disease are increased blood LDL-C levels, yellow tumors, corneal arch and early-onset coronary artery disease. The clinical manifestations of pure congeners are much more severe than those of heterozygotes. the clinical manifestations of patients with FH depend on their genotype, and non-genetic factors also have an impact on them. the relationship between FH genotype and phenotype is complex, and the clinical manifestations vary widely even among individuals with the same mutation, or even those belonging to the same family. In addition, non-genetic factors such as advanced age, male gender, smoking and diet can also significantly affect LDL levels and increase the incidence of coronary heart disease. To risk factors. 1, hyperlipidemia The plasma cholesterol concentration of heterozygotes is usually 2 to 3 times higher than normal, and that of pure heterozygotes is 6 to 8 times higher than normal. The former ranges from 300 mg/dL to 400 mg/dL, while the latter ranges from 600 mg/dL to 1,200 mg/dL. However, some heterozygotes have an insignificant increase in LDL-C. 2. Yellow tumors Increased plasma LDL-C levels contribute to the deposition of cholesterol in other tissues of the body. Those deposited in tendons are called yellow tumors of tendons, mostly in the Achilles tendon and the extensor tendon of the hand, which are unique to FH; nodular yellow tumors also tend to form at the elbow and below the knee; flat yellow tumors may form at the eyelids. Yellow tumors of tendons become more common with age. 3. Corneal arch Cholesterol infiltration in the cornea results in the formation of corneal arch. Pure congeners can appear before the age of 10, while heterozygotes tend to appear after the age of 30. Corneal arches can also be seen in other types of hyperlipidemia. 4. Atherosclerosis Pure congeners with FH tend to develop signs and symptoms of coronary artery disease around the age of 10. The descending aorta, abdominal aorta, thoracic aorta and pulmonary artery trunk are prone to severe atherosclerosis, and yellow atheroma plaques can be formed on the surface of the heart valves and endocardium. The prognosis is worse for pure heterozygotes with receptor deficiency. Male heterozygotes can develop coronary heart disease at the age of 30-40 years, and female heterozygotes have a later age of onset than males by about 10 years. 5. Other Patients with FH often develop recurrent polyarthritis and tenosynovitis, mainly involving the ankle, knee, wrist and proximal interphalangeal joints, which cannot be suppressed by anti-inflammatory drugs.