When a family member has early coronary/cardiovascular disease, genetic factors should be considered (e.g., father less than 55 years old, mother less than 60 years old). In addition, fatty deposits (xanthomas) in the skin, muscle tendons, irises, and elevated cholesterol levels (LDL-C above 190 mg/dl in adults and LDC-C above 160 mg/dl in children) are clinical indicators of a genetic cause when a member of the family is diagnosed with the disease.

Hereditary dyslipidemia is caused by a dominant mutation in one of three genes involved in LDL metabolism (LDLR gene, PCSK gene, and APOB gene), resulting in loss of function of the gene that reduces LDL-C clearance from plasma and significantly elevated LDL-C concentrations in the blood from birth. If one parent carries the disease-causing mutation, the child has a 50% chance of developing the disease. Furthermore, patients may have normal hyperlipidemia due to lifestyle factors (high-fat diet, inactivity, stress), obesity, age, or other diseases.

It is not recommended because it is inappropriate for patients and wastes time and money on ineffective treatment regimens. Scientific studies have shown that people with genetic mutations (familial hypercholesterolemia) are classified as high-risk and very high-risk groups, with a threefold increase in the risk of coronary heart disease and death compared to the general population (despite having the same blood LDL-C). These two diseases have different danger thresholds and treatment strategies, but they are easily confused or ignored, resulting in treatment of the incorrect target and drug dosage, leading to unwanted complications for the patients.

This is a once-in-a-lifetime genetic test and is enough for diagnosing hypercholesterolemia due to genetic causes. If the results are positive, the mutation carrier will be monitored with an individual treatment plan, during which the LDL-C level in the blood must be monitored periodically to achieve the treatment goal. Therefore, genetic testing does not replace routine blood tests.