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The official name of this gene is “gamma-aminobutyric acid (GABA) A receptor, alpha 1.”
GABRA1 is the gene's official symbol. The GABRA1 gene is also known by other names, listed below.
The GABRA1 gene provides instructions for making one piece, the alpha-1 (α1) subunit, of the GABAA receptor protein. GABAA receptors are made up of different combinations of five protein subunits, each produced from a different gene. (Nineteen different genes provide instructions for GABAA receptor subunits.) These subunits form a hole (pore) in the cell membrane through which negatively charged chlorine atoms (chloride ions) can flow.
A chemical that transmits signals in the brain (a neurotransmitter) called gamma-amino butyric acid (GABA) attaches to GABAA receptors. Once GABA attaches, the pore formed by the subunits opens, and chloride ions flow across the cell membrane. After infancy, chloride ions flow into the cell through the open pore, which creates an environment in the cell that blocks (inhibits) signaling between neurons. The primary role of GABA in children and adults is to prevent the brain from being overloaded with too many signals. In contrast, in newborns and infants, chloride ions flow out of the cell when the pore is opened, creating an environment that allows signaling between neurons.
The GABRA1 gene belongs to a family of genes called LGIC (ligand-gated ion channels).
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.
A mutation in the GABRA1 gene has been identified in at least one family with juvenile myoclonic epilepsy. This condition typically begins in childhood or adolescence and causes recurrent myoclonic seizures, which are characterized by rapid, uncontrolled muscle jerks. Affected individuals can also have other types of seizures called generalized tonic-clonic seizures (or grand mal seizures) and absence seizures. The mutation associated with this condition changes a single protein building block (amino acid) in the α1 subunit. The amino acid alanine at protein position 322 is replaced by the amino acid asparagine. This gene mutation is written as Ala322Asp or A322D.
This GABRA1 gene mutation leads to the formation of an abnormal α1 subunit that reduces GABAA receptor function. GABAA receptors containing the abnormal subunit are broken down before they reach the cell membrane. Studies show that the altered receptors can also interfere with normal receptors inside the cell, leading to the additional loss of normal receptors. Because of the reduction of GABAA receptor function, signaling between neurons is not regulated, which can lead to overstimulation of neurons. Researchers believe that the overstimulation of certain neurons in the brain triggers the abnormal brain activity associated with seizures.
Cytogenetic Location: 5q34
Molecular Location on chromosome 5: base pairs 161,847,190 to 161,899,958
The GABRA1 gene is located on the long (q) arm of chromosome 5 at position 34.
More precisely, the GABRA1 gene is located from base pair 161,847,190 to base pair 161,899,958 on chromosome 5.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
You and your healthcare professional may find the following resources about GABRA1 helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
alanine ; amino acid ; asparagine ; cell ; cell membrane ; chloride ; epilepsy ; GABA ; gamma-aminobutyric acid ; gene ; ions ; juvenile ; mutation ; precursor ; protein ; receptor ; subunit
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).
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.