|http://ghr.nlm.nih.gov/ A service of the U.S. National Library of Medicine®|
The official name of this gene is “neurofilament, heavy polypeptide.”
NEFH is the gene's official symbol. The NEFH gene is also known by other names, listed below.
The NEFH gene provides instructions for making a protein component (subunit) of neurofilaments. Neurofilaments make up a structural framework that helps to define the shape and size of nerve cells (neurons). Neurofilaments are assembled from light, medium, and heavy subunits. The heavy subunit is produced from the NEFH gene.
Neurofilaments cross-link with one other, forming bridges that help maintain the diameter of the fiber, or axon, that extends from a neuron. Maintaining a proper axon diameter is important for the transmission of nerve impulses. Neurofilaments are particularly abundant in motor neurons, which are specialized nerve cells in the brain and spinal cord that control muscle movement.
The heavy subunit is made up of three regions: the head, which regulates assembly of neurofilaments; a coiled midsection; and a tail with branches that interact with other proteins (including other neurofilaments). The tail region has a segment called the KSP motif that plays an important role in regulating the functions of neurofilaments.
Mutations in the NEFH gene increase the chances of developing amyotrophic lateral sclerosis (ALS), a condition characterized by progressive movement problems and muscle wasting. Most of these mutations delete or insert DNA building blocks (nucleotides) in the NEFH gene, which produces a KSP motif that is shorter or longer than normal. The abnormal KSP motif may disrupt cross-linking between neurofilaments. One NEFH gene mutation that can lead to ALS changes a single protein building block (amino acid) used to make the heavy subunit. The effect of this mutation is unknown, but it may impair the assembly of neurofilaments.
It is not known how NEFH gene mutations raise the risk of developing ALS. Disrupted cross-linking or impaired assembly of neurofilaments may lead to the accumulation of these filaments in motor neurons. A buildup of neurofilaments in deteriorating motor neurons appears to be an early feature of ALS. It is unclear, however, whether these deposits play a role in causing this disorder or are a byproduct of dying motor neurons.
Cytogenetic Location: 22q12.2
Molecular Location on chromosome 22: base pairs 29,480,191 to 29,491,289
The NEFH gene is located on the long (q) arm of chromosome 22 at position 12.2.
More precisely, the NEFH gene is located from base pair 29,480,191 to base pair 29,491,289 on chromosome 22.
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 NEFH 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.
amino acid ; cross-link ; diameter ; DNA ; gene ; motif ; motor ; mutation ; neurofilament ; neuron ; protein ; sclerosis ; subunit ; wasting
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (/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.