Lecithin cholesterol acyltransferase deficiency

(Redirected from Norum disease)
Jump to navigation Jump to search

WikiDoc Resources for Lecithin cholesterol acyltransferase deficiency

Articles

Most recent articles on Lecithin cholesterol acyltransferase deficiency

Most cited articles on Lecithin cholesterol acyltransferase deficiency

Review articles on Lecithin cholesterol acyltransferase deficiency

Articles on Lecithin cholesterol acyltransferase deficiency in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Lecithin cholesterol acyltransferase deficiency

Images of Lecithin cholesterol acyltransferase deficiency

Photos of Lecithin cholesterol acyltransferase deficiency

Podcasts & MP3s on Lecithin cholesterol acyltransferase deficiency

Videos on Lecithin cholesterol acyltransferase deficiency

Evidence Based Medicine

Cochrane Collaboration on Lecithin cholesterol acyltransferase deficiency

Bandolier on Lecithin cholesterol acyltransferase deficiency

TRIP on Lecithin cholesterol acyltransferase deficiency

Clinical Trials

Ongoing Trials on Lecithin cholesterol acyltransferase deficiency at Clinical Trials.gov

Trial results on Lecithin cholesterol acyltransferase deficiency

Clinical Trials on Lecithin cholesterol acyltransferase deficiency at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Lecithin cholesterol acyltransferase deficiency

NICE Guidance on Lecithin cholesterol acyltransferase deficiency

NHS PRODIGY Guidance

FDA on Lecithin cholesterol acyltransferase deficiency

CDC on Lecithin cholesterol acyltransferase deficiency

Books

Books on Lecithin cholesterol acyltransferase deficiency

News

Lecithin cholesterol acyltransferase deficiency in the news

Be alerted to news on Lecithin cholesterol acyltransferase deficiency

News trends on Lecithin cholesterol acyltransferase deficiency

Commentary

Blogs on Lecithin cholesterol acyltransferase deficiency

Definitions

Definitions of Lecithin cholesterol acyltransferase deficiency

Patient Resources / Community

Patient resources on Lecithin cholesterol acyltransferase deficiency

Discussion groups on Lecithin cholesterol acyltransferase deficiency

Patient Handouts on Lecithin cholesterol acyltransferase deficiency

Directions to Hospitals Treating Lecithin cholesterol acyltransferase deficiency

Risk calculators and risk factors for Lecithin cholesterol acyltransferase deficiency

Healthcare Provider Resources

Symptoms of Lecithin cholesterol acyltransferase deficiency

Causes & Risk Factors for Lecithin cholesterol acyltransferase deficiency

Diagnostic studies for Lecithin cholesterol acyltransferase deficiency

Treatment of Lecithin cholesterol acyltransferase deficiency

Continuing Medical Education (CME)

CME Programs on Lecithin cholesterol acyltransferase deficiency

International

Lecithin cholesterol acyltransferase deficiency en Espanol

Lecithin cholesterol acyltransferase deficiency en Francais

Business

Lecithin cholesterol acyltransferase deficiency in the Marketplace

Patents on Lecithin cholesterol acyltransferase deficiency

Experimental / Informatics

List of terms related to Lecithin cholesterol acyltransferase deficiency

To view Lipoprotein Disorders Main Page Click here
To view Hypolipoproteinemia Main Page Click here
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Aravind Kuchkuntla, M.B.B.S[2]

Synonyms and keywords:LCAT deficiency, dyslipoproteinemic corneal dystrophy, fish eye disease, Norum disease, partial LCAT deficiency, Familial LCAT deficiency

Overview

Lecithin cholesterol acyltransferase (LCAT) is an enzyme with 2 subunits catalyzing the esterification of free cholesterol into cholesterol esters, an important step in the reverse cholesterol transport. LCAT deficiency is a monogenic autosomal recessive disease resulting from mutation in the LCAT gene on chromosome number 16. Patients with homozygous and compound heterozygous mutations are symptomatic due to the accumulation of excessive free cholesterol in the cornea, RBC cell membrane and the kidney. LCAT deficiency is classified into Familial LCAT deficiency(FLD) and Fish Eye Disease (FED) based on the degree of the enzyme function lost. The characteristic feature of these diseases is low plasma HDL C. FLD is a severe form with low HDL C and increase in LDL type protein called lipoprotein-X causing progressive renal failure, FED has a benign course with corneal opacities and low HDL C alone. Low HDL is a risk factor for development of cardiovascular disease,[1]but the risk of developing atherosclerosis and cardiovascular disease in LCAT deficiency is still not well defined and is controversial.[2][3]

Historical Perspective

Classification

LCAT deficiency is classified based on the quantity of enzyme function defective. A mutation in the LCAT gene can cause either a complete loss of function or a partial loss of function which is the basis of LCAT deficiency classification:[8]

  • Familial LCAT deficiency(FLD): Complete loss of alpha and beta LCAT function.
  • Fish Eye Disease (FED): Loss of alpha LCAT function with preserved beta function.[9]
Familial LCAT deficiency (FLD) Fish Eye Disease (FED)
Enzyme Function Completely dysfunctional Loss of alpha function only
Clinical Features Corneal opacities, anaemia

and progressive renal disease with proteinuria

Corneal opacities only;

Normal renal function

Microscopy Deposition of free cholesterol and phospholipids in cornea, RBC cell membrane and in the kidney Deposition of free cholesterol and phospholipids in the cornea
Laboratory findings Elevated free cholesterol

HDLC < 10 mg/dL[3] Low Apo A1 and Apo AII Elevated Apo E and triglycerides Low LDL C

Elevated free cholesterol

HDL C < 27 mg/dL

Apo A1<30mg/dl and low Apo AII

Elevated Apo E and triglycerides

Normal LDL and VLDL

Electrophoresis Pre β-1 and α-4 HDL, LDL C with β mobility due to

Lipoprotien-X

Pre β-1and α-4 HDL with normal

pre-β LDL

Treatment Preserve kidney function

Kidney transplant

Human recombinant enzyme replacement

Optimize lipid levels

Responds to statins[10]

Pathophysiology

Pathogenesis

LCAT deficiency is caused by a mutation in the LCAT gene, resulting in disruption of the reverse cholesterol transport.

LCAT Function

 
 
 
LCAT is synthesized in liver and released into circulation and is picked up by HDL C
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Apo A1 activates LCAT associated with HDL, Apo E activates LCAT associated with LDL C
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
LCAT cleaves fatty acid from phosphotidylcholine
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Transfers fatty acid to beta hydroxyl group of free cholesterol taken up by HDL C
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Results in the formation of cholesterol esters which help in maturation of HDL C and also forms lysophosphotidylcholine
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Esterification of free cholesterol taken up by HDL C, is α-LCAT activity. Esterification of free cholesterol associated with Apo B( LDL C), is β-LCAT activity. This differentiation into alpha and beta is based on the HDL and LDL mobility on electrophoresis[11]
 
 
 

LCAT Deficiency

 
 
 
Loss of LCAT function
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Loss of alpha function leads to failure of HDL maturation resulting in elevated FC, phospholipids, Apo E, pre beta HDL, and low Apo A1 and Apo A2 levels
 
 
 
Loss of beta function results in elevated FC, phospholipids, and formation of cholesterol rich multilamellar particles called Lipoprotein X [14], which are implicated in the development of glomerulopathy[15] [16].

Genetics

LCAT deficiency presents the following genetic characteristics:

Microscopy

Microscopic and histopathological examinations of tissues in LCAT deficiency will reveal the following:

Epidemiology and Demographics

  • The prevalence of Familial LCAT deficiency rare and is estimated to be less than 1/1,000,000. About 125 cases have been reported to date worldwide.[20]
  • Majority of the cases are reported in Europe, Japan and Canada.

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

The most common features of clinical presentation include annular corneal opacity, hemolytic anemia and renal disease.[23] The common presenting features include:

Physical Examination

Physical examination of patients with LCAT deficiency is remarkable for the following:

Laboratory Findings

Laboratory findings consistent with the diagnosis of Familial LCAT deficiency include:

Electrophoresis

2D gel electrophoresis in FLD is remarkable for the following:[26]

Low HDL C differential diagnosis

Familial LCAT

Deficiency

Fish Eye

Disease

Homozygous Tangier

Disease

Heterozygous Tangier

Disease

Apo A1 Deficiency
Gene Defect LCAT LCAT ABCA1 ABCA1 Apo A1
Inheritance Autosomal Recessive Autosomal Recessive Autosomal Recessive Autosomal Recessive Autosomal Dominant
Pathogenesis
  • Loss of alpha and beta LCAT function
  • Failure of cholesterol ester formation.
Loss of alpha function only

Pre beta-1 HDL fails to picks up free cholesterol from cells due to mutation in ABCA1 transporter.

Similar to homozygous Defective synthesis of Apo A1 resulting in failure of maturation of HDL and defective reverse cholesterol transport.
Clinical Features
  • Annular corneal opacity
  • Anaemia
  • Progressive renal disease with proteinuria
  • Corneal opacities only
  • Normal renal function
  • Large yellow-orange tonsils
  • Dense central corneal opacity
  • Relapsing and remitting course of neuropathy
Asymptomatic
  • Corneal Opacities
  • Tuboeruptive, Planar and palmar Xanthomas
  • Premature Heart Disease
Lipid Panel
  • Elevated Free cholesterol
  • HDL-C < 10 mg/dL
  • Low Apo A1 and Apo AII
  • Elevated Apo E and Triglycerides
  • Low LDL C
  • Elevated free cholesterol
  • HDL C < 27 mg/dL
  • Apo A1<30mg/dl and low Apo A2
  • Elevated Apo E and Triglycerides
  • Normal LDL and VLDL
  • HDL < 5% of normal
  • Apo A1 < 1% of normal
  • LDL < 40% of normal
  • HDL C, Apo A1 and LDL 50% less than normal.
  • Undetectable Apo A1
  • HDL C less than 10mg/dl
  • Normal or low Apo AII
  • LDL C normal
  • Triglyceride normal or elevated
2D Gel Electrophoresis Pre β-1 and α-4 HDL, LDL with β mobility due to Lipoprotien-X Pre β-1and α-4 HDL with normal pre-β LDL. Only preβ-1 HDL present
  • Lack of large α-1 and α-2 HDL particles
  • Normal preβ-1 HDL
Lack of Apo A1 containing HDL particles.

Treatment

Medical Therapy

The mainstay of therapy for Familial LCAT deficiency include:

While there is no definitive medical therapy to treat LCAT deficiency, the following methods can help mitigate complications and alleviate symptoms:

Surgery

  • Patients dependent on hemodialysis with worsening renal function are indicated for renal transplant.
    • Lipid abnormalities usually recur after a renal transplant .[31]

Prevention

  • There are no screening recommendations for the disease. Patients are advised regular follow up, medication compliance and monitoring of the renal function to prevent progressive decline in renal function.

References

  1. Goff DC, Lloyd-Jones DM, Bennett G, Coady S, D'Agostino RB, Gibbons R; et al. (2014). "2013 ACC/AHA guideline on the assessment of cardiovascular risk: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines". Circulation. 129 (25 Suppl 2): S49–73. doi:10.1161/01.cir.0000437741.48606.98. PMID 24222018.
  2. Calabresi L, Baldassarre D, Castelnuovo S, Conca P, Bocchi L, Candini C; et al. (2009). "Functional lecithin: cholesterol acyltransferase is not required for efficient atheroprotection in humans". Circulation. 120 (7): 628–35. doi:10.1161/CIRCULATIONAHA.108.818143. PMID 19687369.
  3. 3.0 3.1 3.2 Ossoli A, Simonelli S, Vitali C, Franceschini G, Calabresi L (2016). "Role of LCAT in Atherosclerosis". J Atheroscler Thromb. 23 (2): 119–27. doi:10.5551/jat.32854. PMID 26607351.
  4. GLOMSET JA (1962). "The mechanism of the plasma cholesterol esterification reaction: plasma fatty acid transferase". Biochim Biophys Acta. 65: 128–35. PMID 13948499.
  5. Norum KR, Gjone E (1967). "Familial serum-cholesterol esterification failure. A new inborn error of metabolism". Biochim Biophys Acta. 144 (3): 698–700. PMID 6078131.
  6. Gjone E, Norum KR (1968). "Familial serum cholesterol ester deficiency. Clinical study of a patient with a new syndrome". Acta Med Scand. 183 (1–2): 107–12. PMID 5669813.
  7. McLean J, Wion K, Drayna D, Fielding C, Lawn R (1986). "Human lecithin-cholesterol acyltransferase gene: complete gene sequence and sites of expression". Nucleic Acids Res. 14 (23): 9397–406. PMC 311966. PMID 3797244.
  8. McIntyre N (1988). "Familial LCAT deficiency and fish-eye disease". J Inherit Metab Dis. 11 Suppl 1: 45–56. PMID 3141686.
  9. Funke H, von Eckardstein A, Pritchard PH, Albers JJ, Kastelein JJ, Droste C; et al. (1991). "A molecular defect causing fish eye disease: an amino acid exchange in lecithin-cholesterol acyltransferase (LCAT) leads to the selective loss of alpha-LCAT activity". Proc Natl Acad Sci U S A. 88 (11): 4855–9. PMC 51765. PMID 2052566.
  10. Dimick SM, Sallee B, Asztalos BF, Pritchard PH, Frohlich J, Schaefer EJ (2014). "A kindred with fish eye disease, corneal opacities, marked high-density lipoprotein deficiency, and statin therapy". J Clin Lipidol. 8 (2): 223–30. doi:10.1016/j.jacl.2013.11.005. PMID 24636183.
  11. 11.0 11.1 Asztalos BF, Schaefer EJ, Horvath KV, Yamashita S, Miller M, Franceschini G; et al. (2007). "Role of LCAT in HDL remodeling: investigation of LCAT deficiency states". J Lipid Res. 48 (3): 592–9. doi:10.1194/jlr.M600403-JLR200. PMID 17183024.
  12. Chen CH, Albers JJ (1982). "Distribution of lecithin-cholesterol acyltransferase (LCAT) in human plasma lipoprotein fractions. Evidence for the association of active LCAT with low density lipoproteins". Biochem Biophys Res Commun. 107 (3): 1091–6. PMID 7138515.
  13. Tall AR (1990). "Plasma high density lipoproteins. Metabolism and relationship to atherogenesis". J Clin Invest. 86 (2): 379–84. doi:10.1172/JCI114722. PMC 296738. PMID 2200802.
  14. Narayanan S (1984). "Biochemistry and clinical relevance of lipoprotein X." Ann Clin Lab Sci. 14 (5): 371–4. PMID 6476782.
  15. 15.0 15.1 Ossoli A, Neufeld EB, Thacker SG, Vaisman B, Pryor M, Freeman LA; et al. (2016). "Lipoprotein X Causes Renal Disease in LCAT Deficiency". PLoS One. 11 (2): e0150083. doi:10.1371/journal.pone.0150083. PMC 4769176. PMID 26919698.
  16. Lynn EG, Siow YL, Frohlich J, Cheung GT, O K (2001). "Lipoprotein-X stimulates monocyte chemoattractant protein-1 expression in mesangial cells via nuclear factor-kappa B." Kidney Int. 60 (2): 520–32. doi:10.1046/j.1523-1755.2001.060002520.x. PMID 11473635.
  17. Funke H, von Eckardstein A, Pritchard PH, Hornby AE, Wiebusch H, Motti C; et al. (1993). "Genetic and phenotypic heterogeneity in familial lecithin: cholesterol acyltransferase (LCAT) deficiency. Six newly identified defective alleles further contribute to the structural heterogeneity in this disease". J Clin Invest. 91 (2): 677–83. doi:10.1172/JCI116248. PMC 288009. PMID 8432868.
  18. Gotoda T, Yamada N, Murase T, Sakuma M, Murayama N, Shimano H; et al. (1991). "Differential phenotypic expression by three mutant alleles in familial lecithin:cholesterol acyltransferase deficiency". Lancet. 338 (8770): 778–81. PMID 1681161.
  19. Naghashpour M, Cualing H (2009). "Splenomegaly with sea-blue histiocytosis, dyslipidemia, and nephropathy in a patient with lecithin-cholesterol acyltransferase deficiency: a clinicopathologic correlation". Metabolism. 58 (10): 1459–64. doi:10.1016/j.metabol.2009.04.033. PMID 19592052.
  20. "Orphanet: LCAT deficiency".
  21. Hirano K, Kachi S, Ushida C, Naito M (2004). "Corneal and macular manifestations in a case of deficient lecithin: cholesterol acyltransferase". Jpn J Ophthalmol. 48 (1): 82–4. doi:10.1007/s10384-003-0007-1. PMID 14767661.
  22. Suda T, Akamatsu A, Nakaya Y, Masuda Y, Desaki J (2002). "Alterations in erythrocyte membrane lipid and its fragility in a patient with familial lecithin:cholesterol acyltrasferase (LCAT) deficiency". J Med Invest. 49 (3–4): 147–55. PMID 12323004.
  23. Hrycek A, Cieślik P, Trzeciak HI (1994). "[Clinical features of lecithin-cholesterol acyltransferase deficiency]". Przegl Lek. 51 (12): 516–9. PMID 7746888.
  24. Saeedi R, Li M, Frohlich J (2015). "A review on lecithin:cholesterol acyltransferase deficiency". Clin Biochem. 48 (7–8): 472–5. doi:10.1016/j.clinbiochem.2014.08.014. PMID 25172171.
  25. Rader DJ, Ikewaki K, Duverger N, Schmidt H, Pritchard H, Frohlich J; et al. (1994). "Markedly accelerated catabolism of apolipoprotein A-II (ApoA-II) and high density lipoproteins containing ApoA-II in classic lecithin: cholesterol acyltransferase deficiency and fish-eye disease". J Clin Invest. 93 (1): 321–30. doi:10.1172/JCI116962. PMC 293770. PMID 8282802.
  26. Schaefer EJ, Anthanont P, Diffenderfer MR, Polisecki E, Asztalos BF (2016). "Diagnosis and treatment of high density lipoprotein deficiency". Prog Cardiovasc Dis. 59 (2): 97–106. doi:10.1016/j.pcad.2016.08.006. PMID 27565770.
  27. Schaefer EJ, Santos RD, Asztalos BF (2010). "Marked HDL deficiency and premature coronary heart disease". Curr Opin Lipidol. 21 (4): 289–97. doi:10.1097/MOL.0b013e32833c1ef6. PMID 20616715.
  28. Shamburek RD, Bakker-Arkema R, Auerbach BJ, Krause BR, Homan R, Amar MJ; et al. (2016). "Familial lecithin:cholesterol acyltransferase deficiency: First-in-human treatment with enzyme replacement". J Clin Lipidol. 10 (2): 356–67. doi:10.1016/j.jacl.2015.12.007. PMC 4826469. PMID 27055967.
  29. Simonelli S, Tinti C, Salvini L, Tinti L, Ossoli A, Vitali C; et al. (2013). "Recombinant human LCAT normalizes plasma lipoprotein profile in LCAT deficiency". Biologicals. 41 (6): 446–9. doi:10.1016/j.biologicals.2013.09.007. PMID 24140107.
  30. Aranda P, Valdivielso P, Pisciotta L, Garcia I, Garcã A-Arias C, Bertolini S; et al. (2008). "Therapeutic management of a new case of LCAT deficiency with a multifactorial long-term approach based on high doses of angiotensin II receptor blockers (ARBs)". Clin Nephrol. 69 (3): 213–8. PMID 18397721.
  31. Ahmad SB, Miller M, Hanish S, Bartlett ST, Hutson W, Barth RN; et al. (2016). "Sequential kidney-liver transplantation from the same living donor for lecithin cholesterol acyl transferase deficiency". Clin Transplant. 30 (10): 1370–1374. doi:10.1111/ctr.12826. PMID 27490864.


Template:WikiDoc Sources