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Genes in the bHLH family provide instructions for transcription factors known as basic helix-loop-helix proteins. Transcription factors are proteins that attach (bind) to specific regions of DNA and help control the activity of particular genes. The basic helix-loop-helix proteins are critical in controlling (regulating) many pathways during development.
Basic helix-loop-helix transcription factors contain a region in the protein called a basic helix-loop-helix domain. This domain allows the protein to bind to another protein (dimerize) and then to DNA. When the proteins bind to DNA, they control the activity of particular genes. Some basic helix-loop-helix proteins can turn on (activate) certain genes and others turn off (repress) certain genes.
Basic helix-loop-helix proteins play a role in many cellular and developmental processes, including cell growth and division and development of body systems in the embryo. Mutations in bHLH genes can have a number of effects, such as abnormal development of the heart, mental delays, cancer, and bone abnormalities. Mutations in the bHLH gene MESP2 result in malformation of the spine and ribs seen in spondylothoracic dysostosis and spondylocostal dysostosis.
The HUGO Gene Nomenclature Committee (HGNC) provides an index of gene families (http://www.genenames.org/cgi-bin/genefamilies/) and their member genes.
Genetics Home Reference summarizes the normal function and health implications of these members of the bHLH gene family: EPAS1, HES7, MESP2, MITF, MYCN, TCF4, and TWIST1.
Genetics Home Reference includes these conditions related to genes in the bHLH gene family:
You may find the following resources about the bHLH gene family helpful.
cancer ; cell ; DNA ; domain ; embryo ; gene ; malformation ; mesoderm ; oncogene ; posterior ; protein ; transcription ; transcription factor
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
These sources were used to develop the Genetics Home Reference summary for the bHLH gene family.
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.