The European Atherosclerosis Society (EAS) has listed criteria for the diagnosis of homozygous familial hypercholesterolemia.
Criteria - one of the following:
(1) 2 mutant alleles: LDLR, APOB, PCSK9, LDLRAP1
(2) both of the following:
(2a) one of the following:
(2a1) untreated LDL cholesterol > 500 mg/dL (> 13 mmol/L)
(2a2) treated LDL cholesterol > 300 mg/dL (>= 8 mmol/L)
(2b) one of the following:
(2b1) cutaneous or tendon xanthoma before 10 years of age
(2b2) untreated LDL cholesterol elevated in both parents AND consistent with heterozygous familial hypercholesterolemia
where:
• The LDL cholesterol cut-offs are not absolute.
• A lower untreated LDL cholesterol in a child does not exclude the diagnosis.
• A lower treated LDL cholesterol does not exclude the diagnosis, especially if the patient is being aggressively treated.
• The genetic criteria is probably 2 alleles at the same locus for "homozygous".
