Hepatic lipase deficiency

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Hepatic lipase deficiency is a disorder that affects the body's ability to break down fats (lipids). People with this disorder have increased amounts of certain fats, known as triglycerides and cholesterol, in the blood. These individuals also have increased amounts of molecules known as high-density lipoproteins (HDLs) and decreased amounts of molecules called low-density lipoproteins (LDL). These molecules transport triglycerides and cholesterol throughout the body. In people with hepatic lipase deficiency, the LDL molecules are often abnormally large.

Normally, high levels of HDL (known as "good cholesterol") and low levels of LDL (known as "bad cholesterol") are protective against an accumulation of fatty deposits on the artery walls (atherosclerosis) and heart disease. However, some individuals with hepatic lipase deficiency, who have this imbalance of HDL and LDL, develop atherosclerosis and heart disease in mid-adulthood, while others do not. It is unknown whether people with hepatic lipase deficiency have a greater risk of developing atherosclerosis or heart disease than individuals in the general population. Similarly, it is unclear how increased blood triglycerides and cholesterol levels affect the risk of atherosclerosis and heart disease in people with hepatic lipase deficiency.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Hepatic lipase deficiency is caused by mutations in the LIPC gene. This gene provides instructions for making an enzyme called hepatic lipase. This enzyme is produced by liver cells and released into the bloodstream where it helps convert very low-density lipoproteins (VLDLs) and intermediate-density lipoproteins (IDLs) to LDLs. The enzyme also assists in transporting HDLs that carry cholesterol and triglycerides from the blood to the liver, where the HDLs deposit these fats so they can be redistributed to other tissues or removed from the body.

LIPC gene mutations prevent the release of hepatic lipase from the liver or decrease the enzyme's activity in the bloodstream. As a result, VLDLs and IDLs are not efficiently converted into LDLs, and HDLs carrying cholesterol and triglycerides remain in the bloodstream. It is unclear what effect this change in lipid levels has on people with hepatic lipase deficiency.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Hepatic lipase deficiency is likely a rare disorder; only a few affected families have been reported in the scientific literature.

Understanding terms used in the source

These definitions explain medical words used above. A definition is not evidence that another condition is present, and it does not predict how a symptom will develop. Ask the clinician which terms apply to the actual examination or test result.

Atherosclerosis

A condition characterized by patchy atheromas or atherosclerotic plaques which develop in the walls of medium-sized and large arteries and can lead to arterial stenosis with reduced or blocked blood flow.

Affected

This term applies to a family member who is diagnosed with the same condition as the individual who is the primary focus of investigation (the proband).

Which doctor should you see?

The suggested department for discussing Hepatic lipase deficiency is Clinical Genetics, with a clinical geneticist as the relevant type of clinician. Paediatrician (children) or physician (adults), with clinical geneticist referral.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Does the exact genetic or chromosome finding explain the observed features?
• Would a genetic counsellor help the family understand the result?
• Which organ-specific assessments are appropriate for this particular diagnosis?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Hepatic lipase deficiency. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.