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Genetics Home Reference: your guide to understanding genetic conditions
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LAMA2

Reviewed September 2013

What is the official name of the LAMA2 gene?

The official name of this gene is “laminin, alpha 2.”

LAMA2 is the gene's official symbol. The LAMA2 gene is also known by other names, listed below.

What is the normal function of the LAMA2 gene?

The LAMA2 gene provides instructions for making a part (subunit) of certain members of a protein family called laminins. Laminin proteins are made of three different subunits called alpha, beta, and gamma. There are several forms of each subunit, and each form is produced from instructions carried by a different gene. The LAMA2 gene provides instructions for the alpha-2 subunit. This subunit, together with the beta-1 and gamma-1 subunits, forms the laminin 2 protein, also known as merosin or laminin-211. The alpha-2 subunit, along with the beta-2 and gamma-1 subunits, also forms another laminin called laminin 4, sometimes known as laminin-221.

Laminins are found in an intricate lattice of proteins and other molecules that forms in the spaces between cells (the extracellular matrix). There, the laminins help regulate cell growth, cell movement (motility), and the attachment of cells to one another (adhesion). They are also involved in the formation and organization of basement membranes, which are thin, sheet-like structures within the extracellular matrix that separate and support cells in many tissues. Laminin 2 and laminin 4 play a particularly important role in the muscles used for movement (skeletal muscles). The laminins attach (bind) to other proteins in the extracellular matrix and in the membrane of muscle cells, which helps maintain the stability of muscle fibers.

Does the LAMA2 gene share characteristics with other genes?

The LAMA2 gene belongs to a family of genes called LAM (laminins).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.

How are changes in the LAMA2 gene related to health conditions?

LAMA2-related muscular dystrophy - caused by mutations in the LAMA2 gene

More than 100 LAMA2 gene mutations have been identified in individuals with LAMA2-related muscular dystrophy, a disorder that causes weakness and wasting (atrophy) of skeletal muscles. This condition generally appears in one of two ways: as a severe, early-onset type or a milder, late-onset form. Most LAMA2 gene mutations that cause early-onset LAMA2-related muscular dystrophy result in the absence of functional laminin alpha-2 subunit. Mutations that cause late-onset LAMA2-related muscular dystrophy usually result in a reduction (deficiency) of functional laminin alpha-2 subunit. Deficiency or absence of the laminin alpha-2 subunit results in a corresponding lack of laminin 2 and laminin 4, reducing the strength and stability of muscle tissue and leading to the signs and symptoms of LAMA2-related muscular dystrophy.

Where is the LAMA2 gene located?

Cytogenetic Location: 6q22-q23

Molecular Location on chromosome 6: base pairs 128,883,140 to 129,516,565

The LAMA2 gene is located on the long (q) arm of chromosome 6 between positions 22 and 23.

The LAMA2 gene is located on the long (q) arm of chromosome 6 between positions 22 and 23.

More precisely, the LAMA2 gene is located from base pair 128,883,140 to base pair 129,516,565 on chromosome 6.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about LAMA2?

You and your healthcare professional may find the following resources about LAMA2 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the LAMA2 gene or gene products?

  • LAMA2_HUMAN
  • laminin-2 subunit alpha
  • laminin-4 subunit alpha
  • laminin-12 subunit alpha
  • laminin M chain
  • laminin subunit alpha-2
  • laminin subunit alpha-2 isoform a precursor
  • laminin subunit alpha-2 isoform b precursor
  • LAMM
  • merosin heavy chain

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding LAMA2?

atrophy ; basement membranes ; cell ; deficiency ; extracellular ; extracellular matrix ; gene ; muscle cells ; muscular dystrophy ; precursor ; protein ; subunit ; tissue ; wasting

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Allamand V, Guicheney P. Merosin-deficient congenital muscular dystrophy, autosomal recessive (MDC1A, MIM#156225, LAMA2 gene coding for alpha2 chain of laminin). Eur J Hum Genet. 2002 Feb;10(2):91-4. (http://www.ncbi.nlm.nih.gov/pubmed/11938437?dopt=Abstract)
  • Gavassini BF, Carboni N, Nielsen JE, Danielsen ER, Thomsen C, Svenstrup K, Bello L, Maioli MA, Marrosu G, Ticca AF, Mura M, Marrosu MG, Soraru G, Angelini C, Vissing J, Pegoraro E. Clinical and molecular characterization of limb-girdle muscular dystrophy due to LAMA2 mutations. Muscle Nerve. 2011 Nov;44(5):703-9. doi: 10.1002/mus.22132. Epub 2011 Sep 26. (http://www.ncbi.nlm.nih.gov/pubmed/21953594?dopt=Abstract)
  • Geranmayeh F, Clement E, Feng LH, Sewry C, Pagan J, Mein R, Abbs S, Brueton L, Childs AM, Jungbluth H, De Goede CG, Lynch B, Lin JP, Chow G, Sousa Cd, O'Mahony O, Majumdar A, Straub V, Bushby K, Muntoni F. Genotype-phenotype correlation in a large population of muscular dystrophy patients with LAMA2 mutations. Neuromuscul Disord. 2010 Apr;20(4):241-50. doi: 10.1016/j.nmd.2010.02.001. Epub 2010 Mar 6. (http://www.ncbi.nlm.nih.gov/pubmed/20207543?dopt=Abstract)
  • Jones KJ, Morgan G, Johnston H, Tobias V, Ouvrier RA, Wilkinson I, North KN. The expanding phenotype of laminin alpha2 chain (merosin) abnormalities: case series and review. J Med Genet. 2001 Oct;38(10):649-57. Review. (http://www.ncbi.nlm.nih.gov/pubmed/11584042?dopt=Abstract)
  • Miyagoe-Suzuki Y, Nakagawa M, Takeda S. Merosin and congenital muscular dystrophy. Microsc Res Tech. 2000 Feb 1-15;48(3-4):181-91. Review. (http://www.ncbi.nlm.nih.gov/pubmed/10679965?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/3908)
  • OMIM: LAMININ, ALPHA-2 (http://omim.org/entry/156225)

 

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: September 2013
Published: July 21, 2014