The most important key selective screening points are positive family history for premature CHD and elevated LDL-C levels.
Phenotypic diagnosis should be made using blood cholesterol testing
LDL-C > 190 mg/dL on two different blood samples performed at baseline and after a three-months period of nutrition and lifestyle treatment is highly suggestive of a diagnosis of FH.
LDL-C > 160 mg/dL and a positive family history of premature CHD in first degree relative and/or high blood cholesterol in first degree relative indicates a highly probable diagnosis of FH.
LDL-C > 130 mg/dL and a parent with genetic diagnosis of FH is indicative of probable FH
Secondary causes of hypercholesterolaemia should be ruled out
DNA testing is the gold standard of the diagnosis. When a pathogenic LDL-R mutation is found in a first degree relative, children and/or adolescent should also be genetically tested.
In case of a parent’s death for CHD, a child with hypercholesterolaemia (even if mild) should be tested genetically for FH and Lp(a) levels should be assayed.