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The official name of this gene is “dopamine receptor D5.”
DRD5 is the gene's official symbol. The DRD5 gene is also known by other names, listed below.
The DRD5 gene provides instructions for making a protein called dopamine receptor D5, which is found in the brain. This protein works together with a chemical messenger (neurotransmitter) called dopamine. Dopamine fits into the D5 receptor like a key in a lock, which triggers chemical reactions within nerve cells. Dopamine signaling has many critical functions in the brain, including regulation of attention, mood, memory, learning, and movement.
The DRD5 gene belongs to a family of genes called GPCR (G protein-coupled receptors).
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.
Several studies have examined a possible relationship between a common variation (polymorphism) in the DRD5 gene and benign essential blepharospasm. The results of these studies have been mixed. Some research has suggested that the polymorphism, a short repeated segment of DNA known as allele 2, occurs more often in people with benign essential blepharospasm than in people without the disorder. However, other studies have found no connection between this polymorphism and benign essential blepharospasm. Researchers are still working to clarify whether variants in the DRD5 gene are associated with this disorder.
Other polymorphisms in the DRD5 gene appear to be associated with a common behavioral condition called attention deficit hyperactivity disorder (ADHD). This condition, which typically begins in childhood, is characterized by overactivity, impulsive behavior, and difficulty paying attention.
Most studies of the DRD5 gene and ADHD have focused on a polymorphism located near the beginning of the gene. The region consists of two DNA building blocks (base pairs) that are repeated multiple times in a row. The size of this segment ranges from 134 to 156 base pairs. Multiple studies have suggested that a particular variant, which is 148-base pairs long, is associated with a moderately increased risk of ADHD. However, it is unclear how this polymorphism affects the risk of the disorder.
Variations in the DRD5 gene are among many factors under study to help explain the causes of ADHD. A large number of genetic and environmental factors, most of which remain unknown, likely determine the risk of developing this complex condition.
Cytogenetic Location: 4p16.1
Molecular Location on chromosome 4: base pairs 9,783,257 to 9,785,632
The DRD5 gene is located on the short (p) arm of chromosome 4 at position 16.1.
More precisely, the DRD5 gene is located from base pair 9,783,257 to base pair 9,785,632 on chromosome 4.
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 DRD5 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.
ADHD ; allele ; attention deficit hyperactivity disorder ; benign ; Ca ; class ; DNA ; dopamine ; gene ; hyperactivity ; microsatellite ; polymorphism ; protein ; receptor
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.