Reviewed April 2013
What is the official name of the ACTG1 gene?
The official name of this gene is “actin gamma 1.”
ACTG1 is the gene's official symbol. The ACTG1 gene is also known by other names, listed below.
What is the normal function of the ACTG1 gene?
The ACTG1 gene provides instructions for making a protein called gamma (γ)-actin, which is part of the actin protein family. Proteins in this family are organized into a network of fibers called the actin cytoskeleton, which makes up the structural framework inside cells. There are six types of actin; four are present only in muscle cells, where they are involved in the tensing of muscle fibers (muscle contraction). The other two actin proteins, γ-actin and beta (β)-actin (produced from the ACTB gene), are found in cells throughout the body. These proteins play important roles in determining cell shape and controlling cell movement (motility).
γ-actin is particularly abundant in certain cells in the intestines and the inner ear. Within the inner ear, this protein is found in specialized cells called hair cells, which are essential for normal hearing.
How are changes in the ACTG1 gene related to health conditions?
- Baraitser-Winter syndrome - caused by mutations in the ACTG1 gene
At least six mutations in the ACTG1 gene have been found to cause Baraitser-Winter syndrome, a rare condition that affects the development of the brain, eyes, and other facial features. The known mutations change single protein building blocks (amino acids) in γ-actin. The most common mutation replaces the amino acid serine with the amino acid phenylalanine at protein position 155 (written as Ser155Phe or S155F). The mutations that cause Baraitser-Winter syndrome alter the function of γ-actin, which causes changes in the actin cytoskeleton that modify the structure and organization of cells and affect their ability to move. Because γ-actin is present in cells throughout the body and is involved in many cell activities, problems with its function likely impact many aspects of development. These changes underlie the variety of signs and symptoms associated with Baraitser-Winter syndrome.
- nonsyndromic deafness - caused by mutations in the ACTG1 gene
Researchers have identified at least 10 ACTG1 gene mutations that cause a form of nonsyndromic deafness called DFNA20/26. "Nonsyndromic" means the hearing loss is not associated with signs and symptoms affecting other parts of the body.
The ACTG1 gene mutations that cause nonsyndromic hearing loss change single amino acids in γ-actin, which most likely alters the 3-dimensional shape of the protein. The altered protein probably causes hearing loss by impairing the function or survival of hair cells in the inner ear.
It is unclear why some ACTG1 gene mutations result in nonsyndromic hearing loss while others cause the more severe features of Baraitser-Winter syndrome.
Where is the ACTG1 gene located?
Cytogenetic Location: 17q25
Molecular Location on chromosome 17: base pairs 81,509,970 to 81,512,889
The ACTG1 gene is located on the long (q) arm of chromosome 17 at position 25.
More precisely, the ACTG1 gene is located from base pair 81,509,970 to base pair 81,512,889 on chromosome 17.
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 ACTG1?
You and your healthcare professional may find the following resources about ACTG1 helpful.
Educational resources - Information pages
- Molecular Cell Biology (fourth edition, 2000): Actin and Myosin in Nonmuscle Cells (http://www.ncbi.nlm.nih.gov/books/NBK21562/)
- Neuroscience (second edition, 2001): Hair Cells and the Mechanoelectrical Transduction of Sound Waves (http://www.ncbi.nlm.nih.gov/books/NBK10867/)
- The Cell, A Molecular Approach (second edition, 2000): Structure and Organization of Actin Filaments (http://www.ncbi.nlm.nih.gov/books/NBK9908/)
- Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/books/NBK1434)
Genetic Testing Registry - Repository of genetic test information
- GTR: Genetic tests for ACTG1 (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=71%5Bgeneid%5D)
You may also be interested in these resources, which are designed for genetics professionals and researchers.
- PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/pubmed?term=%28%28ACTG1%5BTIAB%5D%29%20OR%20%28DFNA20%5BTIAB%5D%29%20OR%20%28DFNA26%5BTIAB%5D%29%29%20OR%20%28%28gamma%201%5BTI%5D%29%20AND%20%28actin%5BTI%5D%29%29%20AND%20%28%28Genes%5BMH%5D%29%20OR%20%28Genetic%20Phenomena%5BMH%5D%29%29%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%203600%20days%22%5Bdp%5D)
- OMIM - Genetic disorder catalog (http://omim.org/entry/102560)
Research Resources - Tools for researchers
- Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://atlasgeneticsoncology.org/Genes/GC_ACTG1.html)
- GeneCards (http://www.genecards.org/cgi-bin/carddisp.pl?id_type=entrezgene&id=71)
- HGNC Gene Symbol Report (http://www.genenames.org/cgi-bin/gene_symbol_report?q=data/hgnc_data.php&hgnc_id=144)
- NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/71)
- The Hereditary Hearing Loss Homepage (http://hereditaryhearingloss.org/)
What other names do people use for the ACTG1 gene or gene products?
- actin, cytoplasmic 2
- actin, gamma 1
- actin-like protein
- cytoskeletal gamma-actin
- deafness, autosomal dominant 20
- deafness, autosomal dominant 26
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 ACTG1?
amino acid ;
autosomal dominant ;
hair cells ;
muscle cells ;
You may find definitions for these and many other terms in the Genetics Home Reference
- Bryan KE, Wen KK, Zhu M, Rendtorff ND, Feldkamp M, Tranebjaerg L, Friderici KH, Rubenstein PA. Effects of human deafness gamma-actin mutations (DFNA20/26) on actin function. J Biol Chem. 2006 Jul 21;281(29):20129-39. Epub 2006 May 10. (http://www.ncbi.nlm.nih.gov/pubmed/16690605?dopt=Abstract)
- Dugina V, Zwaenepoel I, Gabbiani G, Clément S, Chaponnier C. Beta and gamma-cytoplasmic actins display distinct distribution and functional diversity. J Cell Sci. 2009 Aug 15;122(Pt 16):2980-8. doi: 10.1242/jcs.041970. Epub 2009 Jul 28. (http://www.ncbi.nlm.nih.gov/pubmed/19638415?dopt=Abstract)
- NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/71)
- Rendtorff ND, Zhu M, Fagerheim T, Antal TL, Jones M, Teslovich TM, Gillanders EM, Barmada M, Teig E, Trent JM, Friderici KH, Stephan DA, Tranebjaerg L. A novel missense mutation in ACTG1 causes dominant deafness in a Norwegian DFNA20/26 family, but ACTG1 mutations are not frequent among families with hereditary hearing impairment. Eur J Hum Genet. 2006 Oct;14(10):1097-105. Epub 2006 Jun 14. (http://www.ncbi.nlm.nih.gov/pubmed/16773128?dopt=Abstract)
- Rivière JB, van Bon BW, Hoischen A, Kholmanskikh SS, O'Roak BJ, Gilissen C, Gijsen S, Sullivan CT, Christian SL, Abdul-Rahman OA, Atkin JF, Chassaing N, Drouin-Garraud V, Fry AE, Fryns JP, Gripp KW, Kempers M, Kleefstra T, Mancini GM, Nowaczyk MJ, van Ravenswaaij-Arts CM, Roscioli T, Marble M, Rosenfeld JA, Siu VM, de Vries BB, Shendure J, Verloes A, Veltman JA, Brunner HG, Ross ME, Pilz DT, Dobyns WB. De novo mutations in the actin genes ACTB and ACTG1 cause Baraitser-Winter syndrome. Nat Genet. 2012 Feb 26;44(4):440-4, S1-2. doi: 10.1038/ng.1091. (http://www.ncbi.nlm.nih.gov/pubmed/22366783?dopt=Abstract)
- van Wijk E, Krieger E, Kemperman MH, De Leenheer EM, Huygen PL, Cremers CW, Cremers FP, Kremer H. A mutation in the gamma actin 1 (ACTG1) gene causes autosomal dominant hearing loss (DFNA20/26). J Med Genet. 2003 Dec;40(12):879-84. (http://www.ncbi.nlm.nih.gov/pubmed/14684684?dopt=Abstract)
- Zhu M, Yang T, Wei S, DeWan AT, Morell RJ, Elfenbein JL, Fisher RA, Leal SM, Smith RJ, Friderici KH. Mutations in the gamma-actin gene (ACTG1) are associated with dominant progressive deafness (DFNA20/26). Am J Hum Genet. 2003 Nov;73(5):1082-91. Epub 2003 Sep 16. (http://www.ncbi.nlm.nih.gov/pubmed/13680526?dopt=Abstract)
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
See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.