Lipoprotein disorders classification: Difference between revisions

	Lipoprotein Disorders Microchapters
Patient Information
Overview
Causes
Classification Hyperlipoproteinemia Hypolipoproteinemia
Treatment

VisualWikitext

Revision as of 14:14, 22 October 2012

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Template:DiseaseDisorder infobox

Overview

Hyperlipidemias are classified according to the Fredrickson classification which is based on the pattern of lipoproteins on electrophoresis or ultracentrifugation.^[1] It was later adopted by the World Health Organization (WHO). It does not directly account for HDL, and it does not distinguish among the different genes that may be partially responsible for some of these conditions. It remains a popular system of classification, but is considered dated by many.

Classification

**Fredrickson classification of Hyperlipidemias**
Hyperlipoproteinemia	Synonyms	Problems	Labs description	Treatment
Type I	Buerger-Gruetz syndrome, Primary hyperlipoproteinaemia, or Familial hyperchylomicronemia	Decreased lipoprotein lipase (LPL) or altered ApoC2	Elevated Chylomicrons	Diet Control
Type IIa	Polygenic hypercholesterolaemia or Familial hypercholesterolemia	LDL receptor deficiency	Elevated LDL only	Bile Acid Sequestrants, Statins, Niacin
Type IIb	Combined hyperlipidemia	Decreased LDL receptor and Increased ApoB	Elevated LDL, VLDL and Triglycerides	Statins, Niacin, Gemfibrozil
Type III	Familial Dysbetalipoproteinemia	Defect in ApoE synthesis	Increased IDL	Drug of choice: Gemfibrozil
Type IV	Endogenous Hyperlipemia	Increased VLDL production and Decreased elimination	Increased VLDL	Drug of choice: Niacin
Type V	Familial Hypertriglyceridemia	Increased VLDL production and Decreased LPL	Increased VLDL and Chylomicrons	Niacin, Gemfibrozil

Unclassified forms

Non-classified forms are extremely rare:

Hypo-alpha lipoproteinemia
Hypo-beta lipoproteinemia (prevalence 0.01-0.1%)

References

↑ Frederickson DS, Lee RS. A system for phenotyping hyperlipidemia. Circulation 1965;31:321-7. PMID 14262568.

External links

Hyperlipoproteinemia	OMIM	GPnotebook	WebMD	Others
Type I	Online Mendelian Inheritance in Man (OMIM) 238600	Template:GPnotebook	.	MeritCare
Type IIa	Online Mendelian Inheritance in Man (OMIM) 144400	Template:GPnotebook	.	Merck
Type IIb	Online Mendelian Inheritance in Man (OMIM) 144400	Template:GPnotebook	.	Merck
Type III	.	Template:GPnotebook	WebMD	Yahoo
Type IV	Online Mendelian Inheritance in Man (OMIM) 144600	Template:GPnotebook	WebMD	Yahoo
Type V	Online Mendelian Inheritance in Man (OMIM) 144600	Template:GPnotebook	.	.

Template:Metabolic pathology

de:Hyperlipoproteinämie he:היפרליפידמיה sv:Hyperlipidemi

Template:WikiDoc Sources

[1] Frederickson DS, Lee RS. A system for phenotyping hyperlipidemia. Circulation 1965;31:321-7. PMID 14262568.

[1]

@@ Line 61: / Line 61: @@
    | [[Niacin]], [[Gemfibrozil]]
 |}
-===Hyperlipoproteinemia type I===
-This very rare form (also known as ''Buerger-Gruetz syndrome'', ''primary hyperlipoproteinaemia'', or ''familial hyperchylomicronemia'') is due to a deficiency of [[lipoprotein lipase]] (LPL) or altered [[apolipoprotein C2]], resulting in elevated [[chylomicron]]s, the particles that transfer fatty acids from the [[digestive tract]] to the [[liver]]. Lipoprotein lipase is also responsible for the initial breakdown of endogenously made triacylglycerides in the form of very low density lipoprotein (VLDL). As such, one would expect a defect in LPL to also result in elevated VLDL. Its prevalence is 0.1% of the population.
-===Hyperlipoproteinemia type II===
-Hyperlipoproteinemia type II, by far the most common form, is further classified into type IIa and type IIb, depending mainly on whether there is elevation in the triglyceride level in addition to LDL cholesterol.
-====Type IIa====
-{{main|Familial hypercholesterolemia}}
-This may be sporadic (due to dietary factors), polygenic, or truly familial as a result of a mutation either in the [[LDL receptor]] gene on [[chromosome 19]] (0.2% of the population) or the [[apolipoprotein B|ApoB]] gene (0.2%). The familial form is characterized by [[Xanthoma|tendon xanthoma]], [[xanthelasma]] and premature cardiovascular disease.
-====Type IIb====
-The high VLDL levels are due to overproduction of substrates, including triglycerides, acetyl CoA, and an increase in B-100 synthesis. They may also be caused by the decreased clearance of LDL. Prevalence in the population is 10%.
-* Familial combined hyperlipoproteinemia (FCH)
-* Secondary combined hyperlipoproteinemia (usually in the context of [[metabolic syndrome]], for which it is a diagnostic criterion)
-===Hyperlipoproteinemia type III===
-This form is due to high [[chylomicron]]s and IDL (intermediate density lipoprotein). Also known as ''broad beta disease'' or ''dysbetalipoproteinemia'', the most common cause for this form is the presence of [[Apolipoprotein E|ApoE]] E2/E2 genotype. It is due to cholesterol-rich VLDL (β-VLDL). Prevalence is 0.02% of the population.
-===Hyperlipoproteinemia type IV===
-This form is due to high [[triglyceride]]s. It is also known as ''[[hypertriglyceridemia]]'' (or ''pure hypertriglyceridemia''). According to the NCEP-ATPIII definition of high triglycerides (>200 mg/dl),
-prevalence is about 16% of adult population.<ref>Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) Final Report.  ''Circulation'' 2002; 106; page 3240</ref>
-===Hyperlipoproteinemia type V===
-This type is very similar to type I, but with high [[VLDL]] in addition to chylomicrons.
-It is also associated with glucose intolerance and hyperuricemia
 ==Unclassified forms==