Homozygous Familial Hypercholesterolemia
Homozygous Familial Hypercholesterolemia
Homozygous familial hypercholesterolemia is a serious inherited lipid metabolism disorder where patients have extremely high LDL-C levels, and can develop skin xanthomas and early-onset atherosclerosis even in childhood.
Start Here
A quick guide to the next step: which department to start with, what to prepare, and what to ask.
Priority should be to visit cardiology or endocrinology departments; pediatric patients should follow up with pediatric cardiology specialists; if chest pain or cardiac symptoms are already present, see cardiology; lipid metabolism specialists or rare disease centers can provide more comprehensive management.
This is one of the most severe forms of familial hypercholesterolemia, where LDL-C is markedly elevated from birth, and children may develop xanthomas and early-onset atherosclerosis risk.
Requires long-term management by lipid metabolism/cardiovascular specialists, which may involve multi-drug combination lipid-lowering therapy, lipoprotein apheresis, coronary risk assessment, and in rare cases more complex treatment options; do not self-apply standard high cholesterol regimens.
Usually related to genes such as LDLR, APOB, PCSK9, and LDLRAP1. Clinically, biallelic variants, compound heterozygous, or functionally near-homozygous severe phenotypes can be seen; genetic interpretation requires combining genetic testing and family information.
Elevated LDL-C in children is often overlooked or attributed to diet; skin xanthomas are easily mistaken for common skin problems; by the time symptoms like chest pain appear, atherosclerosis has often become quite severe.
This page helps patients and families organize care leads. It does not replace a clinician’s diagnosis or treatment plan. For testing, medication, referrals, emergency care, and support applications, follow qualified clinicians, medical institutions, support organizations, and official sources.
Diagnosis Path
Organized around the practical patient journey: identify clues, avoid common delays, then prepare for care.
When to Suspect It
- Yellow or orange papule-like nodules (xanthomas) appearing on the skin, especially on the back of hands, Achilles tendons, elbows, and knees.
- Chest tightness or angina in minors.
- Multiple family members who died young from heart disease or required stents.
- Blood tests showing significantly elevated LDL-C levels (far exceeding normal upper limits; be alert for extremely high levels).
Common Wrong Turns
- Relying solely on diet control without recognizing this as a metabolic disease caused by genetic mutations.
- Skin xanthomas misdiagnosed as common warts or lipomas, without lipid testing.
- Young patients with cardiac symptoms not being investigated for hereditary hypercholesterolemia.
Departments to Start With
- Cardiology
- Endocrinology or lipid metabolism specialists
- Pediatrics (for child patients)
- Dermatology (for xanthoma assessment)
Before the Visit
- Fasting lipid panel: total cholesterol, LDL-C, HDL-C, triglyceride levels.
- Lipoprotein(a) level testing.
- Cardiovascular assessment: carotid ultrasound, echocardiography, coronary CT or coronary angiography (based on age and symptoms).
- Achilles tendon and skin xanthoma examination and documentation.
- Genetic testing to identify mutation types in LDLR, ApoB, PCSK9, LDLRAP1 and other genes.
- Cascade screening of family members.
Tests to Ask About
- What is my specific LDL-C value, and how much higher is it than the normal range?
- Do I need genetic testing to confirm the specific type?
- What cardiovascular tests do I need, and how often should I have follow-up exams?
- How should my family members be screened?
Questions for the Doctor
- What stage is my LDL-C level and atherosclerosis risk currently at?
- What combination of medications or non-drug treatments do I need? What are the treatment goals and monitoring frequency?
- Do I need lipoprotein apheresis or referral to a lipid metabolism/cardiovascular specialist center for evaluation?
- How should family members be screened for lipid and genetic risks?
Basic Information
Medical Notes
More complete medical explanations are kept here for discussion with clinicians.