Hereditary elliptocytosis overview: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 15: Line 15:


Another form of inheritance in HE is [[autosomal recessive]] (AR) ,it is called [[hereditary pyropoikilocytosis]] (HPP), and rarely spontaneous mutations have been reported.<ref name="pmid23664421" />
Another form of inheritance in HE is [[autosomal recessive]] (AR) ,it is called [[hereditary pyropoikilocytosis]] (HPP), and rarely spontaneous mutations have been reported.<ref name="pmid23664421" />
Quality and quantity defects of the cytoskeletal proteins are responsible in Hereditary elliptocytosis. These cytoskeletal proteins are necessary for maintenance of RBCs structure, specially their biconcave morphology.In this disease the protein scaffolding in the inner side of RBC is influenced and results in defective RBCs membrane
Hereditary elliptocytosis is commonly inherited as [[autosomal dominant]]. The only exception is [[autosomal recessive]] inheritance of [[hereditary pyropoikilocytosis]] (HPP). The spontaneous mutations occurs rarely.
The RBC membrane consists of a lipid bilayer and a protein cytoskeleton, which increase RBC resistance, Spectrin is one of the main part of this scaffold and has 2 chains, alpha and beta. Separate genes encode alpha and beta chains and after being twisted together, they create an elongated heterodimer. These heterodimers  build tetramers in the head part and they are linked to other cytoskeletal proteins at the tail regien,[[protein 4.1]] and [[actin]]. Then protein 4.1 and actin bind to glycophorin A, [[band 3]], and [[glycophorin C]], the transmembrane proteins, connecting the scaffold to the lipid bilayer.
Mutations involved in the pathogenesis of HE can occur in each one of the cytoskeletal proteins,such as spectrins, band 4.1 or glycophorin C.
These mutations affect mainly alpha- and beta-spectrin,impairing of the [[spectrin]] [[heterodimer]] formation. The combination of  heterodimer and the lipid anchoring complex can also be influenced.
Normal erythrocytes  remain in the blood circulation for 120 days and they can maintain their elastic recoil and their discoid shape after passing through the capillaries in microcirculation , yet the elliptical shape of RBCs reduces the elasticity of RBCs, so their discoid shape is damaged and their ability to pass through 2 micron capillaries is reduced, so they are  trapped and removed by the spleen. The reduction in surface to volume ratio of RBCs and their premature destruction leads to extravascular hemolysis and the clinical signs and symptoms of these disease.<ref name="pmid24193021">{{cite journal| author=Christensen RD, Nussenzveig RH, Reading NS, Agarwal AM, Prchal JT, Yaish HM| title=Variations in both α-spectrin (SPTA1) and β-spectrin ( SPTB ) in a neonate with prolonged jaundice in a family where nine individuals had hereditary elliptocytosis. | journal=Neonatology | year= 2014 | volume= 105 | issue= 1 | pages= 1-4 | pmid=24193021 | doi=10.1159/000354884 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24193021  }}</ref><ref>{{Cite web|url=https://emedicine.medscape.com/article/199801-overview#showall|title=Hereditary Elliptocytosis|last=|first=|date=|website=|archive-url=|archive-date=|dead-url=|access-date=}}</ref>


==Causes==
==Causes==

Revision as of 04:04, 30 August 2018

Hereditary elliptocytosis Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Hereditary elliptocytosis from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Study of Choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

Chest X Ray

CT

MRI

Ultrasound

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Hereditary elliptocytosis overview On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Hereditary elliptocytosis overview

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Hereditary elliptocytosis overview

CDC on Hereditary elliptocytosis overview

Hereditary elliptocytosis overview in the news

Blogs on Hereditary elliptocytosis overview

Directions to Hospitals Treating Hereditary elliptocytosis

Risk calculators and risk factors for Hereditary elliptocytosis overview

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

Overview

Hereditary elliptocytosis is one of the most common red blood cell membrane disorder in which a large proportion of the erythrocytes (i.e. red blood cells) are elliptical rather than biconcave disc-shaped and it shortens RBC survival. It is also known as ovalocytosis. The main disorder in Hereditary elliptocytosis is cytoskeletal proteins defect,which influence the biconcave appearance of RBCs. patients with HE are usually asymptomatic however they present sometime hemolysis and haemolytic anaemia.[1]

Historical Perspective

RBC anomaly in Hereditary elliptocytosis was first observed in 1860 by Goltz, [2]and Elliptocytosis, elliptical shape of RBCs was described in 1904 by Dresbach. [3] Bishop recognized the familial inheritance as autosomal dominant of HE in 1914 and Hunter and Adams affirmed it's hereditary condition in 1929.[2] Recent studies demonstrate that, the severity of symptoms in patients with Hereditary elliptocytosis is variable and it can be related to genetic variations.[4]

Classification

Pathophysiology

Hereditary elliptocytosis is commonly an autosomal dominant (AD) disorder, in which mutations in alpha-spectrin or beta-spectrin occur, that leads to quantity or structural defects of the cytoskeletal proteins in RBCs. Other cytoskeletal proteins such as glycophorin and band 4.1 can also be mutated in this disease.[5]

Another form of inheritance in HE is autosomal recessive (AR) ,it is called hereditary pyropoikilocytosis (HPP), and rarely spontaneous mutations have been reported.[1]

Quality and quantity defects of the cytoskeletal proteins are responsible in Hereditary elliptocytosis. These cytoskeletal proteins are necessary for maintenance of RBCs structure, specially their biconcave morphology.In this disease the protein scaffolding in the inner side of RBC is influenced and results in defective RBCs membrane

Hereditary elliptocytosis is commonly inherited as autosomal dominant. The only exception is autosomal recessive inheritance of hereditary pyropoikilocytosis (HPP). The spontaneous mutations occurs rarely.

The RBC membrane consists of a lipid bilayer and a protein cytoskeleton, which increase RBC resistance, Spectrin is one of the main part of this scaffold and has 2 chains, alpha and beta. Separate genes encode alpha and beta chains and after being twisted together, they create an elongated heterodimer. These heterodimers  build tetramers in the head part and they are linked to other cytoskeletal proteins at the tail regien,protein 4.1 and actin. Then protein 4.1 and actin bind to glycophorin A, band 3, and glycophorin C, the transmembrane proteins, connecting the scaffold to the lipid bilayer.

Mutations involved in the pathogenesis of HE can occur in each one of the cytoskeletal proteins,such as spectrins, band 4.1 or glycophorin C.

These mutations affect mainly alpha- and beta-spectrin,impairing of the spectrin heterodimer formation. The combination of  heterodimer and the lipid anchoring complex can also be influenced.

Normal erythrocytes remain in the blood circulation for 120 days and they can maintain their elastic recoil and their discoid shape after passing through the capillaries in microcirculation , yet the elliptical shape of RBCs reduces the elasticity of RBCs, so their discoid shape is damaged and their ability to pass through 2 micron capillaries is reduced, so they are  trapped and removed by the spleen. The reduction in surface to volume ratio of RBCs and their premature destruction leads to extravascular hemolysis and the clinical signs and symptoms of these disease.[6][7]

Causes

Differentiating Hereditary elliptocytosis overview from Other Diseases

Epidemiology and Demographics

Risk Factors

Hereditary elliptocytosis is one of the most common RBC membrane disorders worldwide,and the incidence of HE is 25-50 per 100,000 individuals.

The prevalence of Hereditary elliptocytosis is 50 out of 100,000 affected cases in Northern European countries and North America.[1]

In endemic areas for malaria,the incidence of HE is notably higher, this incidence ranges from a low of 600 per 100,000 persons in equatorial Africa to a high of 30,000 per 100,000 persons in Malayan aborigines.

This large number of prevalence is because of relative resistance of elliptocytes against malaria in the endemic areas.

As many patients with HE are asymptomatic, the true incidence is not known.[8]

Screening

Natural History, Complications, and Prognosis

Natural History

Complications

Prognosis

Diagnosis

Diagnostic Criteria

History and Symptoms

Physical Examination

Laboratory Findings

Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Prevention

References

  1. 1.0 1.1 1.2 Da Costa L, Galimand J, Fenneteau O, Mohandas N (2013). "Hereditary spherocytosis, elliptocytosis, and other red cell membrane disorders". Blood Rev. 27 (4): 167–78. doi:10.1016/j.blre.2013.04.003. PMID 23664421.
  2. 2.0 2.1 "Hereditary elliptocytic anaemia" (PDF).
  3. Dresbach M (1904). "ELLIPTICAL HUMAN RED CORPUSCLES". Science. 19 (481): 469–70. doi:10.1126/science.19.481.469. PMID 17730874.
  4. Tse WT, Lux SE (1999). "Red blood cell membrane disorders". Br J Haematol. 104 (1): 2–13. PMID 10027705. Check |pmid= value (help).
  5. Harper SL, Sriswasdi S, Tang HY, Gaetani M, Gallagher PG, Speicher DW (2013). "The common hereditary elliptocytosis-associated α-spectrin L260P mutation perturbs erythrocyte membranes by stabilizing spectrin in the closed dimer conformation". Blood. 122 (17): 3045–53. doi:10.1182/blood-2013-02-487702. PMC 3811177. PMID 23974198.
  6. Christensen RD, Nussenzveig RH, Reading NS, Agarwal AM, Prchal JT, Yaish HM (2014). "Variations in both α-spectrin (SPTA1) and β-spectrin ( SPTB ) in a neonate with prolonged jaundice in a family where nine individuals had hereditary elliptocytosis". Neonatology. 105 (1): 1–4. doi:10.1159/000354884. PMID 24193021.
  7. "Hereditary Elliptocytosis".
  8. Keklik M, Unal A, Sivgin S, Kontas O, Eroglu E, Yilmaz S; et al. (2014). "The coincidence of familial mediterranean Fever and hypereosinophilia in a patient with hereditary elliptocytosis". Indian J Hematol Blood Transfus. 30 (Suppl 1): 138–41. doi:10.1007/s12288-013-0296-6. PMC 4192255. PMID 25332561.

Template:WH Template:WS