E78.01

Familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a genetic disorder characterized by exceptionally high levels of low-density lipoprotein (LDL) cholesterol in the blood. This condition is primarily caused by mutations in the LDLR gene (encoding the LDL receptor), but can also result from mutations in the APOB (apolipoprotein B) or PCSK9 (proprotein convertase subtilisin/kexin type 9) genes. Because the body is unable to effectively clear LDL from the bloodstream, the cholesterol accumulates, leading to premature atherosclerotic cardiovascular disease. There are two main forms: Heterozygous FH (HeFH), which is more common and involves one inherited mutation, and the rare, more severe Homozygous FH (HoFH), where mutations are inherited from both parents. Early diagnosis is crucial, as patients face a significantly elevated risk of myocardial infarction and stroke at a young age if left untreated. Clinical diagnosis often involves the Simon Broome criteria or the Dutch Lipid Clinic Network criteria, assessing LDL levels, family history, and physical markers.

Clinical Symptoms

  • Tendon xanthomas (firm nodules on the Achilles tendon or knuckles)
  • Corneal arcus (a white or gray ring around the iris, especially if occurring before age 45)
  • Xanthelasmas (yellowish cholesterol deposits on the eyelids)
  • Early-onset coronary artery disease (often before age 55 in men and 65 in women)
  • Angina pectoris
  • Myocardial infarction at a young age
  • Sudden cardiac death
  • Bruits over carotid or femoral arteries
  • Aortic stenosis symptoms (specifically in homozygous cases due to supravalvular deposits)

Common Causes

  • Mutation in the Low-Density Lipoprotein Receptor (LDLR) gene
  • Mutation in the Apolipoprotein B (APOB) gene
  • Mutation in the Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) gene
  • Autosomal dominant inheritance pattern
  • Homozygous inheritance (two mutations, resulting in extremely severe phenotype)
  • Heterozygous inheritance (one mutation, resulting in moderately severe phenotype)

Documentation & Coding Tips

Distinguish between phenotypic and genotypic diagnosis.

Example: Patient presents with a clinical phenotype of familial hypercholesterolemia based on Simon Broome criteria, including a pre-treatment LDL-C of 290 mg/dL and presence of Achilles tendon xanthomas. Patient is classified as Heterozygous Familial Hypercholesterolemia (HeFH). This chronic condition requires long-term management with PCSK9 inhibitors and high-potency statins to mitigate the high risk of premature atherosclerotic cardiovascular disease.

Billing Focus: Document whether the diagnosis is based on genetic testing or clinical diagnostic criteria to support E78.01 versus E78.00.

Document specific physical findings indicative of FH.

Example: Physical examination reveals bilateral Achilles tendon xanthomas and corneal arcus in a 34-year-old male. These findings, combined with a family history of myocardial infarction in a first-degree relative at age 40, support the diagnosis of Familial Hypercholesterolemia (E78.01). Condition is stable on Evolocumab 140mg every 2 weeks.

Billing Focus: Specific physical manifestations provide clinical evidence for medical necessity of advanced lipid-lowering therapies.

Explicitly mention Heterozygous (HeFH) vs Homozygous (HoFH) status.

Example: Confirmed Homozygous Familial Hypercholesterolemia (HoFH) via genetic testing (LDLR mutation). Patient has persistent LDL-C over 500 mg/dL despite triple therapy. Initiating LDL apheresis protocol every 2 weeks for aggressive lipid management of this high-risk metabolic condition.

Billing Focus: Specificity of zygosity supports the use of higher-level CPT codes for complex management and prior authorization for specialized drugs.

Report family history as a supporting secondary code.

Example: Patient diagnosed with Familial Hypercholesterolemia (E78.01). Note also includes Z83.42 (Family history of familial hypercholesterolemia) as both parents and one sibling are affected by premature CAD and severe hyperlipidemia. Management focused on lowering LDL-C to goal of less than 55 mg/dL due to high genetic burden.

Billing Focus: Coupling E78.01 with Z83.42 reinforces the clinical validity of the primary diagnosis for audit defense.

Document treatment resistance or intolerance.

Example: Familial Hypercholesterolemia (E78.01) with documented statin intolerance characterized by severe myalgia and CK elevation (M62.82). Transitioning to Bempedoic acid and Ezetimibe combination to manage this chronic metabolic disorder while avoiding further muscle complications.

Billing Focus: Documentation of intolerance is necessary to justify the billing of non-statin therapies under many commercial and Medicare Part D plans.

Identify associated atherosclerotic manifestations.

Example: Patient with known Familial Hypercholesterolemia (E78.01) and established coronary artery disease (I25.10). Documentation of these concurrent conditions reflects the systemic impact of lifelong elevated LDL-C and justifies a High MDM level for today's visit.

Billing Focus: Coding both the underlying genetic lipid disorder and the resulting vascular disease demonstrates clinical complexity.

Relevant CPT Codes

Related Diagnoses

Hierarchy