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The official name of this gene is “kinesin family member 1B.”
KIF1B is the gene's official symbol. The KIF1B gene is also known by other names, listed below.
The KIF1B gene provides instructions for making a protein called kinesin family member 1B, part of the kinesin family of proteins. These proteins are essential for the transport of materials within cells. Kinesin proteins function like freight trains that transport cargo, and their structure is suited for this cargo-carrying function. One part of the protein, called the motor domain, provides the power to move the protein and its cargo along a track-like system made from structures called microtubules. Another part of the kinesin protein, which varies among members of this protein family, binds to specific materials for transport.
Research suggests that the kinesin family member 1B protein specializes in carrying two types of cargo. In nerve cells (neurons), this protein transports small, sac-like structures called synaptic vesicles, which contain materials necessary for the transmission of nerve impulses. In other cell types, the kinesin family member 1B protein carries energy-producing structures called mitochondria.
In addition to its transport functions, the kinesin family member 1B protein appears to be involved in programmed cell death (apoptosis). Apoptosis is a common process throughout life that helps the body get rid of cells it does not need.
The KIF1B gene belongs to a family of genes called KIF (kinesins).
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.
One KIF1B gene mutation has been identified in a small number of individuals with a form of Charcot-Marie-Tooth disease known as type 2A. The mutation changes one of the protein building blocks (amino acids) in the motor domain of kinesin family member 1B. Specifically, the amino acid glutamine is replaced by the amino acid leucine at protein position 98 (written as Gln98Leu or Q98L). Although the effect of this mutation is not fully understood, it probably disrupts the transport of synaptic vesicles. A shortage of synaptic vesicles at nerve endings could impair the transmission of nerve impulses, causing the symptoms of type 2A Charcot-Marie-Tooth disease. However, some researchers question whether KIF1B gene mutations actually play a role in causing this disorder.
Deletion of a region of chromosome 1 containing the KIF1B gene, designated 1p36, has been identified in some people with neuroblastoma, a type of cancerous tumor composed of immature nerve cells (neuroblasts). 1p36 deletions are somatic mutations, which means they occur during a person's lifetime and are present only in the cells that become cancerous. In addition, several inherited KIF1B gene mutations have been identified in families with a history of neuroblastoma. These mutations change single amino acids in the kinesin family member 1B protein. Studies suggest that deletion or mutation of the KIF1B gene may disrupt apoptosis, allowing cells to grow and divide too quickly or in an uncontrolled way. This kind of unregulated cell growth can lead to the formation of tumors.
KIF1B gene mutations have been reported in individuals with a type of paraganglioma called pheochromocytoma. Paragangliomas are noncancerous (benign) tumors of the nervous system. Pheochromocytomas specifically affect the adrenal glands, which are small hormone-producing glands located on top of each kidney. These tumors often cause no symptoms, but in some cases they can produce an excess of hormones that cause dangerously high blood pressure. KIF1B gene mutations are associated with nonsyndromic pheochromocytoma, which means the tumors occur without additional features of an inherited syndrome.
The KIF1B gene mutations identified in nonsyndromic pheochromocytoma change single amino acids in the kinesin family member 1B protein. Studies suggest that the mutations may disrupt apoptosis, allowing cells to grow and divide too quickly or in an uncontrolled way and potentially leading to tumor formation.
A KIF1B gene variation (polymorphism) has also been associated with a higher than average risk of developing multiple sclerosis. Multiple sclerosis is a chronic disorder that affects the brain and spinal cord (the central nervous system), causing muscle weakness, poor coordination, numbness, and a variety of other health problems. Researchers believe that these variations in the KIF1B gene may affect transport of synaptic vessels and mitochondria in neurons, particularly in the specialized extensions called axons that are required for the transmission of nerve impulses. Other genetic and environmental factors also likely affect the risk of developing this complex disorder.
Cytogenetic Location: 1p36.2
Molecular Location on chromosome 1: base pairs 10,270,763 to 10,441,660
The KIF1B gene is located on the short (p) arm of chromosome 1 at position 36.2.
More precisely, the KIF1B gene is located from base pair 10,270,763 to base pair 10,441,660 on chromosome 1.
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 KIF1B 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.
acids ; adrenal glands ; amino acid ; apoptosis ; axons ; benign ; cell ; central nervous system ; chromosome ; chronic ; deletion ; domain ; gene ; hormone ; kidney ; leucine ; mitochondria ; motor ; mutation ; nervous system ; pheochromocytoma ; polymorphism ; protein ; sclerosis ; synaptic vesicles ; syndrome ; tumor
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.