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SEC23B gene
URL of this page: https://medlineplus.gov/genetics/gene/sec23b/

SEC23B gene

SEC23 homolog B, COPII coat complex component

Normal Function

The SEC23B gene provides instructions for making one component of a large group of interacting proteins called coat protein complex II (COPII). COPII is involved in the formation of vesicles, which are small, sac-like structures that transport proteins and other materials within cells. Specifically, COPII triggers the formation of vesicles in a cellular structure called the endoplasmic reticulum (ER), which is involved in protein processing and transport. These COPII vesicles carry proteins that will be exported out of cells (secreted).

The SEC23B protein is very similar to the protein produced from a related gene, SEC23A. These proteins are both components of COPII, and they appear to have overlapping functions. In most types of cells, if one of these proteins is missing, the other may be able to compensate for the loss. However, research indicates that the SEC23B protein may have a unique function in developing red blood cells (erythroblasts).

Health Conditions Related to Genetic Changes

Congenital dyserythropoietic anemia

Variants (also called mutations) in the SEC23B gene have been identified in people with congenital dyserythropoietic anemia (CDA) type II.This condition is characterized by a shortage of red blood cells that is caused by abnormal red blood cell formation (dyserythropoietic anemia). In people with CDA type II, immature red blood cells are unusually shaped and cannot develop into functional, mature cells. As a result, the number of mature and functioning red blood cells decreases, which leads to weakness, yellowing of the skin and eyes (jaundice), an enlarged liver and spleen (hepatosplenomegaly), and the buildup of too much iron (iron overload) in people with CDA type II.

Most SEC23B gene variants change single protein building blocks (amino acids) in the SEC23B protein, likely disrupting its function. It is unclear how SEC23B gene variants cause the characteristic features of CDA type II. It is thought that the decrease in normal SEC23B protein affects erythroblasts because these cells do not have enough SEC23A protein to make up for the loss. This shortage of SEC23B protein leads to the production of irregular erythroblasts that cannot develop into functional, mature red blood cells. The resulting shortage of healthy red blood cells leads to the characteristic signs and symptoms of anemia and the other features of CDA type II.

More About This Health Condition

Cowden syndrome

MedlinePlus Genetics provides information about Cowden syndrome

More About This Health Condition

Other Names for This Gene

  • HEMPAS
  • SC23B_HUMAN
  • transport protein SEC23B

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases

References

  • Denecke J, Marquardt T. Congenital dyserythropoietic anemia type II (CDAII/HEMPAS): where are we now? Biochim Biophys Acta. 2009 Sep;1792(9):915-20. doi: 10.1016/j.bbadis.2008.12.005. Epub 2008 Dec 25. Citation on PubMed
  • Fromme JC, Orci L, Schekman R. Coordination of COPII vesicle trafficking by Sec23. Trends Cell Biol. 2008 Jul;18(7):330-6. doi: 10.1016/j.tcb.2008.04.006. Epub 2008 Jun 3. Citation on PubMed
  • Hughes H, Stephens DJ. Assembly, organization, and function of the COPII coat. Histochem Cell Biol. 2008 Feb;129(2):129-51. doi: 10.1007/s00418-007-0363-x. Epub 2007 Dec 4. Citation on PubMed or Free article on PubMed Central
  • Iolascon A, Andolfo I, Russo R. Congenital dyserythropoietic anemias. Blood. 2020 Sep 10;136(11):1274-1283. doi: 10.1182/blood.2019000948. Citation on PubMed
  • Jing J, Wang B, Liu P. The Functional Role of SEC23 in Vesicle Transportation, Autophagy and Cancer. Int J Biol Sci. 2019 Sep 7;15(11):2419-2426. doi: 10.7150/ijbs.37008. eCollection 2019. Citation on PubMed
  • Russo R, Iolascon A, Andolfo I, Marra R, Rosato BE. Updates on clinical and laboratory aspects of hereditary dyserythropoietic anemias. Int J Lab Hematol. 2024 Aug;46(4):595-605. doi: 10.1111/ijlh.14307. Epub 2024 May 15. Citation on PubMed
  • Schwarz K, Iolascon A, Verissimo F, Trede NS, Horsley W, Chen W, Paw BH, Hopfner KP, Holzmann K, Russo R, Esposito MR, Spano D, De Falco L, Heinrich K, Joggerst B, Rojewski MT, Perrotta S, Denecke J, Pannicke U, Delaunay J, Pepperkok R, Heimpel H. Mutations affecting the secretory COPII coat component SEC23B cause congenital dyserythropoietic anemia type II. Nat Genet. 2009 Aug;41(8):936-40. doi: 10.1038/ng.405. Epub 2009 Jun 28. Citation on PubMed

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