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SMC1A gene

structural maintenance of chromosomes 1A
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Normal Function

The SMC1A gene provides instructions for making a protein that is part of the structural maintenance of chromosomes (SMC) family. Within the nucleus, SMC proteins help regulate the structure and organization of chromosomes.

The protein produced from the SMC1A gene (which is usually called the SMC1 protein) helps control chromosomes during cell division. Before cells divide, they must copy all of their chromosomes. The copied DNA from each chromosome is arranged into two identical structures, called sister chromatids, which are attached to one another during the early stages of cell division. The SMC1 protein is part of a protein group called the cohesin complex that holds the sister chromatids together.

Researchers believe that the SMC1 protein, as a structural component of the cohesin complex, also plays important roles in stabilizing cells' genetic information, repairing damaged DNA, and regulating the activity of certain genes that are essential for normal development.

Health Conditions Related to Genetic Changes

Cornelia de Lange syndrome

More than 35 mutations in the SMC1A gene have been identified in people with Cornelia de Lange syndrome, a developmental disorder that affects many parts of the body. Researchers estimate that mutations in this gene account for about 5 percent of all cases of this condition.

Most of the SMC1A gene mutations that cause Cornelia de Lange syndrome change single protein building blocks (amino acids) in the SMC1 protein. These mutations alter the structure and function of the protein, which likely interferes with the activity of the cohesin complex and impairs its ability to regulate genes that are critical for normal development. Although researchers do not fully understand how these changes cause Cornelia de Lange syndrome, they suspect that altered gene regulation probably underlies many of the developmental problems characteristic of the condition.

Studies suggest that mutations in the SMC1A gene tend to cause a form of Cornelia de Lange syndrome with relatively mild features. Compared to mutations in the NIPBL gene, which are the most common known cause of the disorder, SMC1A gene mutations often cause less significant delays in development and growth and are less likely to cause major birth defects.

More About This Health Condition

Other Names for This Gene

  • DXS423E
  • KIAA0178
  • segregation of mitotic chromosomes 1
  • SMC1
  • SMC1-alpha
  • SMC1A_HUMAN
  • SMC1L1
  • SMCB

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Research Resources

References

  • Borck G, Zarhrate M, Bonnefont JP, Munnich A, Cormier-Daire V, Colleaux L. Incidence and clinical features of X-linked Cornelia de Lange syndrome due to SMC1L1 mutations. Hum Mutat. 2007 Feb;28(2):205-6. Citation on PubMed
  • Deardorff MA, Kaur M, Yaeger D, Rampuria A, Korolev S, Pie J, Gil-RodrĂ­guez C, Arnedo M, Loeys B, Kline AD, Wilson M, Lillquist K, Siu V, Ramos FJ, Musio A, Jackson LS, Dorsett D, Krantz ID. Mutations in cohesin complex members SMC3 and SMC1A cause a mild variant of cornelia de Lange syndrome with predominant mental retardation. Am J Hum Genet. 2007 Mar;80(3):485-94. Epub 2007 Jan 17. Citation on PubMed or Free article on PubMed Central
  • Deardorff MA, Noon SE, Krantz ID. Cornelia de Lange Syndrome. 2005 Sep 16 [updated 2020 Oct 15]. In: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2020. Available from http://www.ncbi.nlm.nih.gov/books/NBK1104/ Citation on PubMed
  • Gervasini C, Russo S, Cereda A, Parenti I, Masciadri M, Azzollini J, Melis D, Aravena T, Doray B, Ferrarini A, Garavelli L, Selicorni A, Larizza L. Cornelia de Lange individuals with new and recurrent SMC1A mutations enhance delineation of mutation repertoire and phenotypic spectrum. Am J Med Genet A. 2013 Nov;161A(11):2909-19. doi: 10.1002/ajmg.a.36252. Epub 2013 Oct 2. Citation on PubMed
  • Liu J, Feldman R, Zhang Z, Deardorff MA, Haverfield EV, Kaur M, Li JR, Clark D, Kline AD, Waggoner DJ, Das S, Jackson LG, Krantz ID. SMC1A expression and mechanism of pathogenicity in probands with X-Linked Cornelia de Lange syndrome. Hum Mutat. 2009 Nov;30(11):1535-42. doi: 10.1002/humu.21095. Citation on PubMed or Free article on PubMed Central
  • Mannini L, Cucco F, Quarantotti V, Krantz ID, Musio A. Mutation spectrum and genotype-phenotype correlation in Cornelia de Lange syndrome. Hum Mutat. 2013 Dec;34(12):1589-96. doi: 10.1002/humu.22430. Epub 2013 Sep 16. Review. Citation on PubMed or Free article on PubMed Central
  • Mannini L, Liu J, Krantz ID, Musio A. Spectrum and consequences of SMC1A mutations: the unexpected involvement of a core component of cohesin in human disease. Hum Mutat. 2010 Jan;31(1):5-10. doi: 10.1002/humu.21129. Review. Citation on PubMed or Free article on PubMed Central
  • Musio A, Selicorni A, Focarelli ML, Gervasini C, Milani D, Russo S, Vezzoni P, Larizza L. X-linked Cornelia de Lange syndrome owing to SMC1L1 mutations. Nat Genet. 2006 May;38(5):528-30. Epub 2006 Apr 9. Citation on PubMed
  • Revenkova E, Focarelli ML, Susani L, Paulis M, Bassi MT, Mannini L, Frattini A, Delia D, Krantz I, Vezzoni P, Jessberger R, Musio A. Cornelia de Lange syndrome mutations in SMC1A or SMC3 affect binding to DNA. Hum Mol Genet. 2009 Feb 1;18(3):418-27. doi: 10.1093/hmg/ddn369. Epub 2008 Nov 7. Citation on PubMed or Free article on PubMed Central
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