Diagnosis and Screening Screening
ÎUniversal screening for elevated serum cholesterol is recommended. FH should be suspected when untreated fasting low-density lipoprotein cholesterol (LDL-C) or non–high-density lipoprotein cholesterol (HDL-C) levels are at or above the following:
• Adults (≥ 20 years): LDL-C ≥ 190 mg/dL or non–HDL-C ≥ 220 mg/dL. • Children, adolescents and young adults (< 20 years): LDL-C ≥ 160 mg/dL or non–HDL-C ≥ 190 mg/dL (total cholesterol minus HDL-C).
ÎFor all individuals with these levels, a family history of high cholesterol and heart disease in first-degree relatives should be collected. The likelihood of FH is higher in individuals with a positive family history of hypercholesterolemia or of premature CHD (onset in men before age 55 years and women before age 65 years).
ÎCholesterol screening should be considered beginning at age 2 for children with a family history of premature cardiovascular disease or elevated cholesterol. All individuals should be screened by age 20.
ÎAlthough not present in many individuals with FH, the following physical findings should prompt the clinician to strongly suspect FH and obtain necessary lipid measurements if not already available:
• Tendon xanthomas at any age (most common in Achilles tendon and finger extensor tendons, but can also occur in patellar and triceps tendons). • Arcus corneae in a patient under age 45.
ÎAt the LDL-C levels listed below the probability of FH is approximately 80% of the general population. These LDL-C levels should prompt the clinician to strongly consider a diagnosis of FH and obtain further family information:
• LDL-C ≥ 250 mg/dL in a patient aged 30 or more. • LDL-C ≥ 220 mg/dL for patients aged 20 to 29. • LDL-C ≥ 190 mg/dL in patients under age 20.
Cascade Screening
ÎLipid testing of first-degree relatives, known as cascade screening, should be offered to all individuals with FH.
ÎAs cascade screening proceeds, newly identified FH cases provide additional relatives who should be considered for screening.
ÎCascade screening is the most cost-effective means of finding previously undiagnosed FH patients and is also cost-effective in terms of cost per year of life saved.
Genetic Screening
ÎGenetic screening for FH is generally not needed for diagnosis or clinical management but may be useful when the diagnosis is uncertain.
ÎIdentification of a causal mutation may provide additional motivation for some patients to implement appropriate treatment.
