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Genes in the GJ gene family provide instructions for producing proteins called connexins. Connexins are one part (subunit) of a structure called a connexon that is found within cell membranes. Six connexins make up one connexon. Connexons allow for cell-to-cell communication by joining with connexons of other cells to form a channel. Many channels clustered together form a gap junction. Gap junctions speed the transport of nutrients, charged particles (ions), and other small molecules that carry signals between cells. Communication through gap junctions helps regulate many different processes, including heart function, cell growth and specialization, and development before birth.
There are 21 known genes in the human GJ gene family. The genes in this family are designated by the letters GJ and an additional letter and number specific to that particular gene, for example GJB2.
Changes in GJ genes are associated with disorders that affect different parts of the body. Specifically, mutations in the GJB1 gene cause one form of Charcot-Marie-Tooth disease, an inherited condition that affects the nervous system. Additionally, mutations in the GJA1 gene cause oculodentodigital dysplasia, a condition that primarily affects the development of the eyes, teeth, and fingers. Other conditions associated with mutations in the GJ genes include deafness, clouding of the lens of the eyes (cataracts), and various skin disorders.
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 GJ gene family: GJA1, GJB1, GJB2, GJB3, GJB4, and GJB6.
Genetics Home Reference includes these conditions related to genes in the GJ gene family:
You may find the following resources about the GJ gene family helpful.
cell ; channel ; charged particles ; dysplasia ; gap junction proteins ; gap junctions ; gene ; inherited ; ions ; nervous system ; protein ; subunit
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 GJ 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.