Lipoprotein disorders

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Lipoprotein Disorders Microchapters

Patient Information

Overview

Causes

Classification

Hyperlipoproteinemia
Hypolipoproteinemia

Treatment

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rim Halaby, M.D. [2], Hardik Patel, M.D., Tarek Nafee, M.D. [3], Prince Tano Djan, BSc, MBChB [4], Aravind Kuchkuntla, M.B.B.S[5], Usama Talib, BSc, MD [6], Shivani Chaparala M.B.B.S [7], Vishal Devarkonda, M.B.B.S[8]

Overview

Lipoproteins, which are aggregates of proteins and lipids, allow the circulation of hydrophobic lipids in the body. Disorders of lipids and lipoproteins metabolism have important health consequences, mainly on the cardiovascular system. Lipoprotein disorders can be described as abnormalities in the level of the lipids, which include cholesterol and triglycerides, or as abnormalities in the levels of lipoproteins that include LDL, HDL, VLDL and chylomicrons.

Lipoprotein disorders have been initially classified in 1967 into different phenotypes by Fredrickson according to the type of lipoproteins that accumulate. However; Fredrickson's classification of hyperlipoproteinemias took into consideration the elevation in chylomicrons, LDL, VLDL but did not include abnormalities in HDL levels. Other classifications have been suggested, one of which is the National Cholesterol Education Program (NCEP) classification of lipoprotein disorders. NCEP classifies lipid disorders according to laboratory cut off points for the levels of total cholesterol, LDL-C and HDL.

Lipoprotein disorders can be classified according to different criteria. First of all, lipoprotein disorders can be classified as primary disorders resulting from genetic mutations and secondary to other diseases. Another way of classifying lipoprotein disorders is as hypolipidemia (or hypolipoproteinemia) and hyperlipidemia (hyperlipoproteinemia) where the lipoprotein levels are decreased and increased respectively. However, the latter classification is not precise and creates some ambiguity, because some people can be labeled as having hyperlipidemia but have simultaneously high level of some lipoproteins and low levels of other lipoproteins depending on the underlying pathophysiology. Hence, a better term to describe the constellation of abnormal lipid profiles is "disorders of lipoproteins", or dyslipoproteinemia or dyslipidemia.

Classification


 
 
 
 
 
 
 
 
 
 
 
 
 
Hyperlipoproteinemia/Hyperlipidemia
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Type I:
Familial hyperchylomicronemia
 
 
Type II
 
Type III:
Dysbetalipoproteinemia
 
Type IV:
Primary hypertriglyceridemia
 
Type V:
Mixed hyperlipoproteinemia
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Type A:
Familial hypercholesterolemia
 
Type B:
Familial combined hyperlipidemia
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Type A
 
Type B
 
Type C
 
 
 
 

Genetics

Shown below is a table summarizing the primary lipoprotein disorders along with the the gene and main lipoprotein involved in each disease:

Genetic Lipoprotein Disorder Gene Involved Main Lipoprotein Involved
Hyperlipoproteinemias Familial hyperchylomicronemia Type I
Familial hypercholesterolemia Type IIA LDL-R LDL
Familial combined hyperlipidemia Type IIB Multiple genes
Dysbetalipoproteinemia type III Apo E
Familial hypertriglyceridemia Type IV Multiple genes
Mixed hyperlipoproteinemia Type V
Autosomal dominant hypercholesterolemia PCSK9 LDL
Autosomal recessive hypercholesterolemia ARH LDL
Familial sitosterolemia ABCG5 - ABCG8 LDL
Familial lipoprotein(a) hyperlipoproteinemia Apo(a) LDL
Familial defective apo B100 Apo B LDL
Hepatic lipase deficiency HL
Lipoprotein lipase deficiency LPL Chylomicron
Apo C-II deficiency Apo C-II Chylomicron
Apo A-V deficiency Apo A-V deficiency Chylomicron
Hypolipoproteinemias Abetalipoproteinemia MTP LDL
Hypobetalipoproteinemia Apo B LDL
Familial hypoalphalipoproteinemia
GPIHBP1 deficiency GPIHBP1 Chylomicron
Apo A-I deficiency Apo A-I HDL
Tangier disease ABCA1 HDL
Familial LCAT deficiency LCAT HDL
CETP deficiency CETP HDL
Type A Niemann-Pick disease SMPD1 HDL
Type B Niemann-Pick disease SMPD1 HDL
Type C Niemann-Pick disease NPC1 HDL
PCSK9 deficiency PCSK9 HDL
Chylomicron retention disease SAR1B Multiple

References

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