Table 1. Diagnostic criteria for pediatric FH (under the age of 15).

1. Hyper-LDL cholesterolemia (untreated LDL-C level ≥ 140 mg/dL, confirmed multiple times)

2. Family history of FH (Parents or siblings）

3. Parental LDL-C ≥ 180 mg/dL or family history of premature coronary artery disease (Grand parent or parent)

After ruling out other primary and secondary Hyper-LDL cholesterolemia,

● Diagnose FH with items 1 and 2.

● Diagnose probable FH with items 1 and 3. If the individual‘s LDL-C is 180 mg/dL or higher, diagnose FH.

● Even if only item 1 is used, ≥ 250 mg/dL is diagnosed with FH and ≥ 180 mg/dL is diagnosed with probable FH.

・Differentiate HoFH when LDL-C is ≥ 250 mg/dL or xanthomas are present.

・Diagnose FH if the individual has a pathogenic gene mutation for FH. If a parent, a brother, or a sister is found to have a pathogenic gene mutation for FH, that is considered to be the family history of FH (item 2).

・Premature coronary artery disease is defined as coronary artery disease occurring at less than 55 years of age in men and less than 65 years of age in women.

・Probable FH cases require further scrutiny and lipid-lowering therapy.