Heterozygous familial hypercholesterolemia can be diagnosed if certain findings are present.

LDL-cholesterol raising genetic defects include:

(1) mutations in LDL-receptor

(2) mutations in apolipoprotein B

(3) mutations in PCSK9


Clinical criteria for heterozygous familial hypercholesterolemia:

(1) >= 1 first-degree relative with one or more of the following:

(1a) serum LDL-C similar to values below

(1b) premature coronary artery disease

(1c) positive genetic testing for an LDL-C-raising genetic defect

(2) one of the following:

(2a) serum LDL-C >= 160 mg/dL in pediatric patient

(2b) serum LDL-C >= 190 mg/dL in adult


Genetic criteria - one of the following:

(1) 1 abnormal LDL-C raising genetic defect

(2) presence of >= 1 LDL-C raising genetic defect(s) AND a LDL-C lowering gene variants AND LDL-C < 160 mg/dL


If a patient has 1 abnormal LDL-C raising genetic defect AND a serum LDL-C > 400 mg/dL, then the patient is treated as a homozygote.

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