Hypolipoproteinemia: Difference between revisions

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===Low HDL Diagnostic Features===
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Revision as of 21:45, 19 November 2016

Lipid Disorders Main Page

Overview

Causes

Classification

Abetalipoproteinemia
Hypobetalipoproteinemia
Familial hypoalphalipoproteinemia
LCAT Deficiency
Chylomicron retention disease
Tangier disease
Familial combined hypolipidemia

Differential Diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mohamed Moubarak, M.D. [2]; Aravind Kuchkuntla, M.B.B.S[3]; Tarek Nafee, M.D. [4]

Synonyms and keywords: Hypolipidemia, low lipoprotein

Overview

Hypolipoproteinemia is defined as low levels of one or more type of lipoproteins. Hypolipidemia, a commonly used term in the clinical practice, describes low level of lipids, whether cholesterol or triglycerides. They are referred to as hypocholesterolemia and hypotriglyceridemia respectively. Despite being commonly used to describe abnormalities in lipid metabolism, the term hypolipidemia is not very specific. For instance, people who have metabolic syndrome have high LDL and low HDL and yet they are described to have hyperlipidemia when their HDL level is decreased. Moreover, some people who have low levels of a specific lipoprotein may have a normal measured total cholesterol and triglyceride levels.

Synopsis

  • It is defined as patients having LDL C less than the 5th percentile when compared to normal population.
  • We have to rule out secondary causes first and then consider screening for rare genetic diseases.
Abetalipoprotienemia Familial Homozygous

Hypobetalipoproteinemia

Familial Heterozygous

Hypobetalipoproteinemia

PCSK9 deficiency Chylomicron Retention

Disease

Familial Combined

Hypolipidemia

LDL C ↓↓↓ (0) ↓↓↓ ↓↓ ↓↓
Apo B ↓↓↓( 0) ↓↓↓ N ↓↓ N
TG ↓↓↓ ↓↓↓ N
TC ↓↓↓ ↓↓↓ ↓↓
HDL ↓↓ ↓↓ N N ↓↓ ↓↓
VLDL ↓↓ ↓↓ N ↓↓
Apo A1 ↓↓ ↓↓ N ↓↓ N

Classification

Shown below is an algorithm depicting the classification of hypolipoproteinemia into primary and secondary.

 
 
 
 
 
 
Hypolipoproteinemia
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Primary
(Genetic)
 
 
 
 
 
 
 
 
 
 
 
 
 
Secondary
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Abetalipoproteinemia
Apolipoprotein 1 deficiency
Chylomicron retention disease
Familial combined hypolipidemia
Hypobetalipoproteinemia
LCAT deficiency
Primary alphalipoproteinemia
PCSK9 deficiency
Tangier disease
 
 
 
 
 
 
 
 
 
 
 
 
 
Anemia
Criticial illness
Chronic inflammation
Chronic liver disease
Hyperthyroidism
Infection
Malabsorption
Malignancy

Diagnostic Approach to Hypolipoproteinemias

Low LDL Diagnostic Algorithm

The following Algorithm may be used to diagnose patients with low LDL hypolipoproteinemias:

 
 
 
 
 
Low LDL C <5th percentile
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Rule out secondary causes of low LDL
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Lipid panel
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Normal Triglycerides
 
 
 
 
Low Triglycerides
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Chlyomicron retention disease
(Confirm with gene sequencing)
 
 
 
 
Screen the lipid panel of the patient's parents
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Normal Parental Lipid Panel
 
 
If Parental Lipid Panel <50% of Normal on:
*LDL
*Total Cholesterol
*Triglycerides
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Hypobetalipoproteinemia
(Confirm with gene sequencing)
 
 
Abetalipoproteinemia
(Confirm with gene sequencing)


Low HDL Diagnostic Features

Familial LCAT

Deficiency

Fish Eye

Disease

Tangier Disease
Clinical Features Corneal opacities, anaemia

and progressive renal disease with proteinuria

Corneal opacities only;

Normal renal function

Characteristic Laboratory Finding

References


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