Dysbetalipoproteinemia: Difference between revisions
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'''To view Lipoprotein disorders main page [[ Lipoprotein disorders | Click here]]'''<br> | |||
'''To view Hyperlipoproteinemia main page [[ Hyperlipoproteinemia | Click here]]''' <br> | |||
{{SK}} Broad beta disease; Broad beta hyperlipoproteinemia; Broad-beta hyperlipoproteinemia; Dysbetalipoproteinemia; Familial dysbetalipoproteinemia; Familial hypercholesterolemia with hyperlipemia; Type III hyperlipoproteinemia; Type 3 hyperlipoproteinemia | |||
==Overview== | ==Overview== | ||
Familial dysbetalipoproteinemia is | Familial dysbetalipoproteinemia is an inheritable, [[autosomal recessive]] disorder in which there are high amounts of [[cholesterol]] and [[triglycerides]] in the [[blood]]. This form of hyperlipoproteinemia, also known as broad beta disease or dysbetalipoproteinemia, occurs due to high levels of [[chylomicrons]] and [[IDL]] (intermediate density lipoprotein). The most common genetic cause of this disease is the presence of the [[Apolipoprotein E|ApoE]] E2/E2 genotype. It is due to cholesterol-rich [[VLDL]] (β-VLDL). The [[prevalence]] of familial dysbetalipoproteinemia is 1 in 5,000-10,000 people in the general population. | ||
==Historical perspective== | ==Historical perspective== | ||
In 1967, Fredrickson classified lipoprotein disorder using paper [[electrophoresis]].<ref name="pmid32961932">{{cite journal| author=Culliton BJ| title=Fredrickson's bitter end at Hughes. | journal=Science | year= 1987 | volume= 236 | issue= 4807 | pages= 1417-8 | pmid=3296193 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3296193 }}</ref> | |||
==Classification== | ==Classification== | ||
There is no established classification system for dysbetalipoproteinemia. | |||
For a detailed classification of [[hyperlipoproteinemia]] click '''[[Hyperlipoproteinemia#Classification|here]]'''. | |||
==Pathophysiology== | ==Pathophysiology== | ||
Dysbetalipoproteinemia is an [[autosomal recessive disorder]] caused by mutations in [[Apo E gene]], which is located on the long arm of chromosome 19(19q13). | |||
* | <ref name="pmid22069485">{{cite journal| author=Georgiadou D, Chroni A, Vezeridis A, Zannis VI, Stratikos E| title=Biophysical analysis of apolipoprotein E3 variants linked with development of type III hyperlipoproteinemia. | journal=PLoS One | year= 2011 | volume= 6 | issue= 11 | pages= e27037 | pmid=22069485 | doi=10.1371/journal.pone.0027037 | pmc=3206067 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22069485}}</ref><ref name="pmid8304363">{{cite journal| author=Zhao SP, Smelt AH, Leuven JA, Vroom TF, van der Laarse A, van 't Hooft FM| title=Changes of lipoprotein profile in familial dysbetalipoproteinemia with gemfibrozil. | journal=Am J Med | year= 1994 | volume= 96 | issue= 1 | pages= 49-56 | pmid=8304363 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8304363 }} </ref><ref name="medline">{{https://medlineplus.gov/ency/article/000402.html}}</ref><ref name="pmid10552997">{{cite journal| author=Mahley RW, Huang Y, Rall SC| title=Pathogenesis of type III hyperlipoproteinemia (dysbetalipoproteinemia). Questions, quandaries, and paradoxes. | journal=J Lipid Res | year= 1999 | volume= 40 | issue= 11 | pages= 1933-49 | pmid=10552997 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10552997 }} </ref><ref name="pmid8185134">{{cite journal| author=Walden CC, Hegele RA| title=Apolipoprotein E in hyperlipidemia. | journal=Ann Intern Med | year= 1994 | volume= 120 | issue= 12 | pages= 1026-36 | pmid=8185134 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8185134 }} </ref> | ||
=== Genetics === | |||
*[[Homozygosity]] for the ApoE2 [[isoform]], which contains two [[cysteine]] residues and has lower binding capacity for the [[LDL]] receptor, is associated with majority of cases with dysbetalipoproteinemia. | |||
*Besides Apo E2, naturally occurring Apo E mutations have also been found to be associated with dysbetalipoproteinemia. These are inherited in a [[Autosomal dominant|dominant mode]] and expressed at an early age. | |||
===Pathogenesis=== | ===Pathogenesis=== | ||
*Remnants of [[chylomicrons]] and [[VLDL]] are cleared from circulation by [[Apolipoprotein E]] | *Remnants of [[chylomicrons]] and [[VLDL]] are cleared from circulation by [[Apolipoprotein E]] | ||
*Apolipoprotein E serving as a ligand for the low-density | *[[Apolipoprotein E]], serving as a [[ligand]] for the [[low-density lipoprotein]] receptor, mediates hepatic clearance of [[chylomicrons]] and [[VLDL remnants]] from circulation. | ||
* | *The most common Apo E isoform is E 3/3, which contains [[cysteine]] at position 112 and [[arginine]] at position 158. | ||
*[[VLDL]] and [[chylomicron]] remnants that contains Apo E2 on their surface are not cleared as efficiently from the [[plasma]], resulting in the formation of dense VLDL particles known as beta-VLDL. | |||
* | *The accumulation of [[VLDL]] and [[chylomicrons]] results in [[atherosclerosis]] and [[dyslipidemia]]. | ||
* | |||
==Causes== | ==Causes== | ||
The cause of type 3 hyperlipidemia | The cause of type 3 hyperlipidemia is genetic. | ||
==Differential | |||
==Differential Diagnosis== | |||
Dysbetalipoproteinemia must be differentiated from all other kinds of hyperlipidemias. On the basis of high triglyceride levels it can be differentiated from: | |||
*[[Familial hyperchylomicronemia]] | |||
*[[Familial hypercholesterolemia]] | |||
*[[Familial combined hyperlipidemia]] | |||
*[[Primary hypertriglyceridemia]]/ [[Primary hypertriglyceridemia]] | |||
*Drugs causing high triglyceride levels:<ref name="pmid25234560">Jacobson TA, Ito MK, Maki KC, Orringer CE, Bays HE, Jones PH et al. (2014) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=25234560 National Lipid Association recommendations for patient-centered management of dyslipidemia: part 1 - executive summary.] ''J Clin Lipidol'' 8 (5):473-88. [http://dx.doi.org/10.1016/j.jacl.2014.07.007 DOI:10.1016/j.jacl.2014.07.007] PMID: [https://pubmed.gov/25234560 25234560]</ref> | |||
**[[Atypical antipsychotic drugs]] ([[Atypical antipsychotic|fluperlapine]], [[clozapine]], [[olanzapine]]), [[beta-blockers]] (especially non-beta 1-selective), [[bile acid sequestrants]], [[cyclophosphamide]], [[glucocorticoids]], [[Immunosuppressive drugs]] ([[cyclosporine]], [[sirolimus]]), [[interferon]], [[L-asparaginase]], [[Estrogens|oral estrogens]], [[protease inhibitors]], [[raloxifene]], [[retinoids]], [[rosiglitazone]], [[tamoxifen]], [[thiazide diuretics]]. | |||
For a detailed differential diagnosis of [[hyperlipoproteinemia]] click '''[[Hyperlipoproteinemia#Differential Diagnosis|here]]'''. | |||
==Epidemiology and Demographics== | ==Epidemiology and Demographics== | ||
The prevalence of dysbetalipoproteinemia is approximately 1 in 5,000-10,000 people in the general population.<ref name="pmid8304363" /><ref name="medline" /> | |||
===Age=== | |||
The majority of cases occur during early adulthood. Rarely, cases have been described in children and the elderly. | |||
*Women are usually affected after [[menopause]]. | |||
===Gender=== | |||
Males are more commonly affected than females. | |||
===Race=== | |||
*Women are usually affected after [[menopause]] | There is no racial predilection for familial dysbetalipoproteinemia. | ||
==Risk Factors== | ==Risk Factors== | ||
Common risk factors in the development of dysbetalipoproteinemia are:<ref name="pmid8304363" /><ref name="medline" /> | |||
*Family history (most important) | |||
*[[Hypothyroidism]] | |||
*[[Obesity]] | |||
*[[Diabetes mellitus|Diabetes]] | |||
*[[Coronary heart disease]] | |||
*[[Kidney disease]] | |||
*[[Alcohol abuse]] | |||
==Screening== | ==Screening== | ||
There are no | There are no established screening recommendations for dysbetalipoproteinemia. | ||
==Natural History, Complication, Prognosis== | ==Natural History, Complication, Prognosis== | ||
===Natural History=== | ===Natural History=== | ||
If left untreated, dysbetalipoproteinemia can lead to [[chronic pancreatitis]], [[atherosclerosis]], [[stroke]], and [[intermittent claudication]]. | |||
===Complications=== | ===Complications=== | ||
Dysbetalipoproteinemia is associated with the following complications:<ref name="pmid12506591">{{cite journal| author=Blom DJ, Byrnes P, Jones S, Marais AD| title=Dysbetalipoproteinaemia--clinical and pathophysiological features. | journal=S Afr Med J | year= 2002 | volume= 92 | issue= 11 | pages= 892-7 | pmid=12506591 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12506591 }} </ref> <ref name="pmid244053722">{{cite journal| author=Marais AD, Solomon GA, Blom DJ| title=Dysbetalipoproteinaemia: a mixed hyperlipidaemia of remnant lipoproteins due to mutations in apolipoprotein E. | journal=Crit Rev Clin Lab Sci | year= 2014 | volume= 51 | issue= 1 | pages= 46-62 | pmid=24405372 | doi=10.3109/10408363.2013.870526 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24405372 }}</ref> | |||
* Atherosclerotic complications | *Atherosclerotic complications (e.g., [[coronary artery disease]]) | ||
*[[Pancreatitis]] | *[[Pancreatitis]] | ||
* [[Stroke]] | *[[Stroke]] | ||
* [[Peripheral vascular disease]] | *[[Peripheral vascular disease]] | ||
* [[Intermittent claudication]] | *[[Intermittent claudication]] | ||
*[[Glomerulopathy]] leading to [[Renal Failure]] | |||
===Prognosis=== | ===Prognosis=== | ||
Patients with dysbetalipoproteinemia have an increased risk for [[coronary artery disease]] and [[peripheral vascular disease]]. With treatment, most people show a significant reduction in [[lipid]] levels and thus associated complications. | |||
==Diagnosis== | ==Diagnosis== | ||
=== | ===Symptoms=== | ||
A detailed history | A detailed history, complete with a focused family history, must be obtained in order to ensure an accurate diagnosis is made. Symptoms of dysbetalipoprotenemia include:<ref name="pmid12506591">{{cite journal| author=Blom DJ, Byrnes P, Jones S, Marais AD| title=Dysbetalipoproteinaemia--clinical and pathophysiological features. | journal=S Afr Med J | year= 2002 | volume= 92 | issue= 11 | pages= 892-7 | pmid=12506591 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12506591 }} </ref><ref name="pmid3042820">{{cite journal| author=Cruz PD, East C, Bergstresser PR| title=Dermal, subcutaneous, and tendon xanthomas: diagnostic markers for specific lipoprotein disorders. | journal=J Am Acad Dermatol | year= 1988 | volume= 19 | issue= 1 Pt 1 | pages= 95-111 | pmid=3042820 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3042820 }} </ref><ref name="pmid24205719">{{cite journal| author=Eto M, Saito M| title=[Familial type III hyperlipoproteinemia]. | journal=Nihon Rinsho | year= 2013 | volume= 71 | issue= 9 | pages= 1590-4 | pmid=24205719 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24205719 }} </ref> | ||
====== Dermatological and musculoskeletal ====== | |||
*Yellow papules [[Xanthomas|(Xanthomas]]) involving [[skin]] and [[tendon]]s may be present. | |||
=== | ===== Cardiac ===== | ||
*[[Chest pain]] can be the presenting complaint signifying cardiac involvement | |||
===== | ===== Vascular ===== | ||
*Leg pain (due to [[peripheral vascular disease]]) | *Leg pain (due to [[peripheral vascular disease]]) | ||
===Physical Exam=== | ===Physical Exam=== | ||
A detailed physical exam is required for patients suspected to have dysbetalipoproteinemia. Physical examination in dysbetalipoproteinemia may range from being normal to the | A detailed physical exam is required for patients suspected to have dysbetalipoproteinemia. Physical examination in dysbetalipoproteinemia may range from being normal to being remarkable for the following findings:<ref name="pmid12506591">{{cite journal| author=Blom DJ, Byrnes P, Jones S, Marais AD| title=Dysbetalipoproteinaemia--clinical and pathophysiological features. | journal=S Afr Med J | year= 2002 | volume= 92 | issue= 11 | pages= 892-7 | pmid=12506591 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12506591 }} </ref> | ||
====Dermatological==== | ====Dermatological==== | ||
*[[Xanthoma]] Striatum palmare-consisting of yellow streaks in the palmar creases | *[[Xanthoma]] Striatum palmare-consisting of yellow streaks in the palmar creases | ||
Line 76: | Line 106: | ||
*Cutaneous [[xanthomas]] | *Cutaneous [[xanthomas]] | ||
====Musculoskeletal==== | ====Musculoskeletal==== | ||
*Tendon [[xanthomas]] may also be seen | *Tendon [[xanthomas]] may also be seen in rare cases | ||
====Vascular==== | ====Vascular==== | ||
*[[Peripheral vascular disease]] | *[[Peripheral vascular disease]] | ||
===Laboratory Findings=== | ===Laboratory Findings=== | ||
The laboratory findings consistent with | The laboratory findings consistent with a diagnosis of dysbetalipoprotenemia include the following:<ref name="pmid10552997">{{cite journal| author=Mahley RW, Huang Y, Rall SC| title=Pathogenesis of type III hyperlipoproteinemia (dysbetalipoproteinemia). Questions, quandaries, and paradoxes. | journal=J Lipid Res | year= 1999 | volume= 40 | issue= 11 | pages= 1933-49 | pmid=10552997 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10552997 }} </ref><ref name="Heart Disease">{{cite book |last=Braunwald |first=Eugene |date= |title=Heart Disease- Fourth Edition |location= Harvard Medical School |publisher=W. B. SAUNDERS COMPANY |page=1137 |isbn=0-7216-3097-9}}</ref> | ||
{| class="wikitable" | {| class="wikitable" | ||
!Appearance | ! rowspan="2" |Appearance | ||
!VLDL cholesterol | ! colspan="4" |Lipid Profile | ||
!Cholesterol | ! rowspan="2" |VLDL cholesterol | ||
! rowspan="2" |Isoelectric focusing | |||
|- | |||
!Total Cholesterol | |||
!Triglycerides | !Triglycerides | ||
! | !LDL | ||
!HDL | |||
|- | |- | ||
|Floating | |Floating | ||
beta lipoproteins | beta lipoproteins | ||
|Elevated | |||
|Elevated | |||
|Decreaesd | |||
|Normal | |||
|[[VLDL]] cholesterol/ | |[[VLDL]] cholesterol/ | ||
VLDL triglyceride >0.35 | VLDL triglyceride >0.35 | ||
|[[ApoE2]] homozygote | |[[ApoE2]] homozygote | ||
|} | |} | ||
=== Molecular Genetic Testing === | === Molecular Genetic Testing === | ||
A diagnosis of dysbetalipoproteinemia can be confirmed by presence of two Apo E2 genes, in the presence of characteristic symptoms.<ref name="pmid27603268">{{cite journal| author=Rothschild M, Duhon G, Riaz R, Jetty V, Goldenberg N, Glueck CJ et al.| title=Pathognomonic Palmar Crease Xanthomas of Apolipoprotein E2 Homozygosity-Familial Dysbetalipoproteinemia. | journal=JAMA Dermatol | year= 2016 | volume= 152 | issue= 11 | pages= 1275-1276 | pmid=27603268 | doi=10.1001/jamadermatol.2016.2223 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27603268 }} </ref> | |||
==Treatment== | ==Treatment== | ||
Options for the treatment of dysbetalipoprotenemia include both medical and non-medical approaches, as described below.<ref>The Measurement of Lipids, Lipoproteins, Apolipoproteins, Fatty Acids, and Sterols, and Next Generation Sequencing for the Diagnosis and Treatment of Lipid Disorders. | |||
Schaefer EJ, Tsunoda F, Diffenderfer M, Polisecki E, Thai N, Asztalos B.</ref><ref name="pmid17100406">{{cite journal| author=Hachem SB, Mooradian AD| title=Familial dyslipidaemias: an overview of genetics, pathophysiology and management. | journal=Drugs | year= 2006 | volume= 66 | issue= 15 | pages= 1949-69 | pmid=17100406 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17100406 }} </ref> | |||
===Non-pharmacological Therapy=== | |||
*[[Exercise]] and dietary therapy involving a low-[[cholesterol]] and low-fat diet have been shown to be effective. | |||
*Patients may also be counseled to avoid other risk factors responsible for complications, such as smoking. | |||
*Inappropriate or subnormal control of the disease with the implementation of non-pharmacological therapies requires pharmacological treatment. | |||
===Medical Therapy=== | ===Medical Therapy=== | ||
*[[Bile acid]] binding agents are an option if [[triglyceride]] levels are < | *[[Bile acid]] binding agents are an option if [[triglyceride]] levels are <200 mg/dL. | ||
*[[Statins]] can be used if [[triglyceride]] levels are < | *[[Statins]] can be used if [[triglyceride]] levels are <500 mg/dL. | ||
*[[Fibrates]] and [[ | *[[Fibrates]] and [[nicotinic acid]] can also be used. | ||
==Prevention== | ==Prevention== | ||
===Primary Prevention=== | |||
* [[Genetic counseling]] is recommended for patients and family members | *[[Genetic counseling]] is recommended for patients and their family members.<ref name="pmid244053722">{{cite journal| author=Marais AD, Solomon GA, Blom DJ| title=Dysbetalipoproteinaemia: a mixed hyperlipidaemia of remnant lipoproteins due to mutations in apolipoprotein E. | journal=Crit Rev Clin Lab Sci | year= 2014 | volume= 51 | issue= 1 | pages= 46-62 | pmid=24405372 | doi=10.3109/10408363.2013.870526 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24405372 }}</ref> | ||
===Secondary | ===Secondary Prevention=== | ||
Measures for the [[secondary prevention]] for dysbetalipoproteinemia include:<ref name="pmid17100406">{{cite journal| author=Hachem SB, Mooradian AD| title=Familial dyslipidaemias: an overview of genetics, pathophysiology and management. | journal=Drugs | year= 2006 | volume= 66 | issue= 15 | pages= 1949-69 | pmid=17100406 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17100406 }} </ref> | |||
*Lifestyle modifications | *Lifestyle modifications | ||
*Screening | *Screening family members to increase the likelihood of early detection and treatment | ||
*Early treatment and | *Early treatment and avoidance of other risk factors for [[vascular disease]] (e.g., [[smoking]]) to prevention of complications | ||
==References== | ==References== | ||
{{Reflist|2}} | {{Reflist|2}} |
Latest revision as of 16:02, 9 August 2017
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Usama Talib, BSc, MD [2], Vishal Devarkonda, M.B.B.S[3]
To view Lipoprotein disorders main page Click here
To view Hyperlipoproteinemia main page Click here
Synonyms and keywords: Broad beta disease; Broad beta hyperlipoproteinemia; Broad-beta hyperlipoproteinemia; Dysbetalipoproteinemia; Familial dysbetalipoproteinemia; Familial hypercholesterolemia with hyperlipemia; Type III hyperlipoproteinemia; Type 3 hyperlipoproteinemia
Overview
Familial dysbetalipoproteinemia is an inheritable, autosomal recessive disorder in which there are high amounts of cholesterol and triglycerides in the blood. This form of hyperlipoproteinemia, also known as broad beta disease or dysbetalipoproteinemia, occurs due to high levels of chylomicrons and IDL (intermediate density lipoprotein). The most common genetic cause of this disease is the presence of the ApoE E2/E2 genotype. It is due to cholesterol-rich VLDL (β-VLDL). The prevalence of familial dysbetalipoproteinemia is 1 in 5,000-10,000 people in the general population.
Historical perspective
In 1967, Fredrickson classified lipoprotein disorder using paper electrophoresis.[1]
Classification
There is no established classification system for dysbetalipoproteinemia. For a detailed classification of hyperlipoproteinemia click here.
Pathophysiology
Dysbetalipoproteinemia is an autosomal recessive disorder caused by mutations in Apo E gene, which is located on the long arm of chromosome 19(19q13). [2][3][4][5][6]
Genetics
- Homozygosity for the ApoE2 isoform, which contains two cysteine residues and has lower binding capacity for the LDL receptor, is associated with majority of cases with dysbetalipoproteinemia.
- Besides Apo E2, naturally occurring Apo E mutations have also been found to be associated with dysbetalipoproteinemia. These are inherited in a dominant mode and expressed at an early age.
Pathogenesis
- Remnants of chylomicrons and VLDL are cleared from circulation by Apolipoprotein E
- Apolipoprotein E, serving as a ligand for the low-density lipoprotein receptor, mediates hepatic clearance of chylomicrons and VLDL remnants from circulation.
- The most common Apo E isoform is E 3/3, which contains cysteine at position 112 and arginine at position 158.
- VLDL and chylomicron remnants that contains Apo E2 on their surface are not cleared as efficiently from the plasma, resulting in the formation of dense VLDL particles known as beta-VLDL.
- The accumulation of VLDL and chylomicrons results in atherosclerosis and dyslipidemia.
Causes
The cause of type 3 hyperlipidemia is genetic.
Differential Diagnosis
Dysbetalipoproteinemia must be differentiated from all other kinds of hyperlipidemias. On the basis of high triglyceride levels it can be differentiated from:
- Familial hyperchylomicronemia
- Familial hypercholesterolemia
- Familial combined hyperlipidemia
- Primary hypertriglyceridemia/ Primary hypertriglyceridemia
- Drugs causing high triglyceride levels:[7]
- Atypical antipsychotic drugs (fluperlapine, clozapine, olanzapine), beta-blockers (especially non-beta 1-selective), bile acid sequestrants, cyclophosphamide, glucocorticoids, Immunosuppressive drugs (cyclosporine, sirolimus), interferon, L-asparaginase, oral estrogens, protease inhibitors, raloxifene, retinoids, rosiglitazone, tamoxifen, thiazide diuretics.
For a detailed differential diagnosis of hyperlipoproteinemia click here.
Epidemiology and Demographics
The prevalence of dysbetalipoproteinemia is approximately 1 in 5,000-10,000 people in the general population.[3][4]
Age
The majority of cases occur during early adulthood. Rarely, cases have been described in children and the elderly.
- Women are usually affected after menopause.
Gender
Males are more commonly affected than females.
Race
There is no racial predilection for familial dysbetalipoproteinemia.
Risk Factors
Common risk factors in the development of dysbetalipoproteinemia are:[3][4]
- Family history (most important)
- Hypothyroidism
- Obesity
- Diabetes
- Coronary heart disease
- Kidney disease
- Alcohol abuse
Screening
There are no established screening recommendations for dysbetalipoproteinemia.
Natural History, Complication, Prognosis
Natural History
If left untreated, dysbetalipoproteinemia can lead to chronic pancreatitis, atherosclerosis, stroke, and intermittent claudication.
Complications
Dysbetalipoproteinemia is associated with the following complications:[8] [9]
- Atherosclerotic complications (e.g., coronary artery disease)
- Pancreatitis
- Stroke
- Peripheral vascular disease
- Intermittent claudication
- Glomerulopathy leading to Renal Failure
Prognosis
Patients with dysbetalipoproteinemia have an increased risk for coronary artery disease and peripheral vascular disease. With treatment, most people show a significant reduction in lipid levels and thus associated complications.
Diagnosis
Symptoms
A detailed history, complete with a focused family history, must be obtained in order to ensure an accurate diagnosis is made. Symptoms of dysbetalipoprotenemia include:[8][10][11]
Dermatological and musculoskeletal
- Yellow papules (Xanthomas) involving skin and tendons may be present.
Cardiac
- Chest pain can be the presenting complaint signifying cardiac involvement
Vascular
- Leg pain (due to peripheral vascular disease)
Physical Exam
A detailed physical exam is required for patients suspected to have dysbetalipoproteinemia. Physical examination in dysbetalipoproteinemia may range from being normal to being remarkable for the following findings:[8]
Dermatological
- Xanthoma Striatum palmare-consisting of yellow streaks in the palmar creases
- Tuberoeruptive xanthomas on the elbow or tibial tuberosities
- Cutaneous xanthomas
Musculoskeletal
- Tendon xanthomas may also be seen in rare cases
Vascular
Laboratory Findings
The laboratory findings consistent with a diagnosis of dysbetalipoprotenemia include the following:[5][12]
Appearance | Lipid Profile | VLDL cholesterol | Isoelectric focusing | |||
---|---|---|---|---|---|---|
Total Cholesterol | Triglycerides | LDL | HDL | |||
Floating
beta lipoproteins |
Elevated | Elevated | Decreaesd | Normal | VLDL cholesterol/
VLDL triglyceride >0.35 |
ApoE2 homozygote |
Molecular Genetic Testing
A diagnosis of dysbetalipoproteinemia can be confirmed by presence of two Apo E2 genes, in the presence of characteristic symptoms.[13]
Treatment
Options for the treatment of dysbetalipoprotenemia include both medical and non-medical approaches, as described below.[14][15]
Non-pharmacological Therapy
- Exercise and dietary therapy involving a low-cholesterol and low-fat diet have been shown to be effective.
- Patients may also be counseled to avoid other risk factors responsible for complications, such as smoking.
- Inappropriate or subnormal control of the disease with the implementation of non-pharmacological therapies requires pharmacological treatment.
Medical Therapy
- Bile acid binding agents are an option if triglyceride levels are <200 mg/dL.
- Statins can be used if triglyceride levels are <500 mg/dL.
- Fibrates and nicotinic acid can also be used.
Prevention
Primary Prevention
- Genetic counseling is recommended for patients and their family members.[9]
Secondary Prevention
Measures for the secondary prevention for dysbetalipoproteinemia include:[15]
- Lifestyle modifications
- Screening family members to increase the likelihood of early detection and treatment
- Early treatment and avoidance of other risk factors for vascular disease (e.g., smoking) to prevention of complications
References
- ↑ Culliton BJ (1987). "Fredrickson's bitter end at Hughes". Science. 236 (4807): 1417–8. PMID 3296193.
- ↑ Georgiadou D, Chroni A, Vezeridis A, Zannis VI, Stratikos E (2011). "Biophysical analysis of apolipoprotein E3 variants linked with development of type III hyperlipoproteinemia". PLoS One. 6 (11): e27037. doi:10.1371/journal.pone.0027037. PMC 3206067. PMID 22069485.
- ↑ 3.0 3.1 3.2 Zhao SP, Smelt AH, Leuven JA, Vroom TF, van der Laarse A, van 't Hooft FM (1994). "Changes of lipoprotein profile in familial dysbetalipoproteinemia with gemfibrozil". Am J Med. 96 (1): 49–56. PMID 8304363.
- ↑ 4.0 4.1 4.2 Template:Https://medlineplus.gov/ency/article/000402.html
- ↑ 5.0 5.1 Mahley RW, Huang Y, Rall SC (1999). "Pathogenesis of type III hyperlipoproteinemia (dysbetalipoproteinemia). Questions, quandaries, and paradoxes". J Lipid Res. 40 (11): 1933–49. PMID 10552997.
- ↑ Walden CC, Hegele RA (1994). "Apolipoprotein E in hyperlipidemia". Ann Intern Med. 120 (12): 1026–36. PMID 8185134.
- ↑ Jacobson TA, Ito MK, Maki KC, Orringer CE, Bays HE, Jones PH et al. (2014) National Lipid Association recommendations for patient-centered management of dyslipidemia: part 1 - executive summary. J Clin Lipidol 8 (5):473-88. DOI:10.1016/j.jacl.2014.07.007 PMID: 25234560
- ↑ 8.0 8.1 8.2 Blom DJ, Byrnes P, Jones S, Marais AD (2002). "Dysbetalipoproteinaemia--clinical and pathophysiological features". S Afr Med J. 92 (11): 892–7. PMID 12506591.
- ↑ 9.0 9.1 Marais AD, Solomon GA, Blom DJ (2014). "Dysbetalipoproteinaemia: a mixed hyperlipidaemia of remnant lipoproteins due to mutations in apolipoprotein E." Crit Rev Clin Lab Sci. 51 (1): 46–62. doi:10.3109/10408363.2013.870526. PMID 24405372.
- ↑ Cruz PD, East C, Bergstresser PR (1988). "Dermal, subcutaneous, and tendon xanthomas: diagnostic markers for specific lipoprotein disorders". J Am Acad Dermatol. 19 (1 Pt 1): 95–111. PMID 3042820.
- ↑ Eto M, Saito M (2013). "[Familial type III hyperlipoproteinemia]". Nihon Rinsho. 71 (9): 1590–4. PMID 24205719.
- ↑ Braunwald, Eugene. Heart Disease- Fourth Edition. Harvard Medical School: W. B. SAUNDERS COMPANY. p. 1137. ISBN 0-7216-3097-9.
- ↑ Rothschild M, Duhon G, Riaz R, Jetty V, Goldenberg N, Glueck CJ; et al. (2016). "Pathognomonic Palmar Crease Xanthomas of Apolipoprotein E2 Homozygosity-Familial Dysbetalipoproteinemia". JAMA Dermatol. 152 (11): 1275–1276. doi:10.1001/jamadermatol.2016.2223. PMID 27603268.
- ↑ The Measurement of Lipids, Lipoproteins, Apolipoproteins, Fatty Acids, and Sterols, and Next Generation Sequencing for the Diagnosis and Treatment of Lipid Disorders. Schaefer EJ, Tsunoda F, Diffenderfer M, Polisecki E, Thai N, Asztalos B.
- ↑ 15.0 15.1 Hachem SB, Mooradian AD (2006). "Familial dyslipidaemias: an overview of genetics, pathophysiology and management". Drugs. 66 (15): 1949–69. PMID 17100406.