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FLNA

FLNA

Reviewed October 2010

What is the official name of the FLNA gene?

The official name of this gene is “filamin A, alpha.”

FLNA is the gene's official symbol. The FLNA gene is also known by other names, listed below.

Read more about gene names and symbols on the About page.

What is the normal function of the FLNA gene?

The FLNA gene provides instructions for producing the protein filamin A, which helps build the network of protein filaments (cytoskeleton) that gives structure to cells and allows them to change shape and move. Filamin A binds to another protein called actin and helps it form the branching network of filaments that make up the cytoskeleton. Filamin A also links actin to many other proteins to perform various functions within the cell, including regulating skeletal and brain development, the formation of blood vessels, and blood clotting.

How are changes in the FLNA gene related to health conditions?

frontometaphyseal dysplasia - caused by mutations in the FLNA gene

A small number of mutations in regions of the FLNA gene called exons 4, 22, 29, 33, and 44 through 46 have been identified in people with frontometaphyseal dysplasia. These mutations are described as "gain-of-function" because they appear to enhance the activity of the filamin A protein or give the protein a new, atypical function. Different mutations appear to produce specific changes in the protein, resulting in particular signs and symptoms that are classified as individual FLNA-related disorders. Researchers believe that the mutations may change the way the filamin A protein helps regulate processes involved in skeletal development, but it is not known how changes in the protein relate to the specific signs and symptoms of frontometaphyseal dysplasia.

intestinal pseudo-obstruction - caused by mutations in the FLNA gene

Intestinal pseudo-obstruction, a condition characterized by impairment of the muscle contractions that move food through the digestive tract (peristalsis), can be caused by mutations in the FLNA gene.

Some individuals with intestinal pseudo-obstruction have FLNA gene mutations that result in an abnormally short filamin A protein. Others have duplications or deletions of genetic material in the FLNA gene. Researchers believe that these genetic changes may impair the function of the filamin A protein, causing abnormalities in the cytoskeleton of nerve cells (neurons) in the gastrointestinal tract. These abnormalities result in impaired peristalsis, which causes abdominal pain and the other gastrointestinal symptoms of intestinal pseudo-obstruction.

Deletions or duplications of genetic material that affect the FLNA gene can also include adjacent genes on the X chromosome. Changes in adjacent genes may account for some of the other signs and symptoms, such as neurological abnormalities and unusual facial features, that occur in some affected individuals.

Melnick-Needles syndrome - caused by mutations in the FLNA gene

A small number of mutations in a region of the FLNA gene called exon 22 have been identified in people with Melnick-Needles syndrome. These mutations are described as "gain-of-function" because they appear to enhance the activity of the filamin A protein or give the protein a new, atypical function. Different mutations appear to produce specific changes in the protein, resulting in particular signs and symptoms that are classified as individual FLNA-related disorders. Researchers believe that the mutations may change the way the filamin A protein helps regulate processes involved in skeletal development, but it is not known how changes in the protein relate to the specific signs and symptoms of Melnick-Needles syndrome.

otopalatodigital syndrome type 1 - caused by mutations in the FLNA gene

A small number of mutations in regions of the FLNA gene called exons 3, 4, and 5 have been identified in people with otopalatodigital syndrome type 1. The mutations all result in changes to the filamin A protein in the region that binds to actin. The mutations responsible for otopalatodigital syndrome type 1 are described as "gain-of-function" because they appear to enhance the activity of the filamin A protein or give the protein a new, atypical function. Different mutations appear to produce specific changes in the protein, resulting in particular signs and symptoms that are classified as individual FLNA-related disorders. Researchers believe that the mutations may change the way the filamin A protein helps regulate processes involved in skeletal development, but it is not known how changes in the protein relate to the specific signs and symptoms of otopalatodigital syndrome type 1.

otopalatodigital syndrome type 2 - caused by mutations in the FLNA gene

A small number of mutations in regions of the FLNA gene called exons 3, 4, and 5 have been identified in people with otopalatodigital syndrome type 2. Similar but more severe symptoms have been associated with mutations in exons 11 and 29. The mutations in exons 3, 4, and 5 result in changes to the filamin A protein in the region that binds to actin. The mutations responsible for otopalatodigital syndrome type 2 are described as "gain-of-function" because they appear to enhance the activity of the filamin A protein or give the protein a new, atypical function. Different mutations appear to produce specific changes in the protein, resulting in particular signs and symptoms that are classified as individual FLNA-related disorders. Researchers believe that the mutations may change the way the filamin A protein helps regulate processes involved in skeletal development, but it is not known how changes in the protein relate to the specific signs and symptoms of otopalatodigital syndrome type 2.

periventricular heterotopia - caused by mutations in the FLNA gene

More than 25 FLNA gene mutations have been identified in individuals with periventricular heterotopia. Most of these mutations result in a protein that is too short and cannot perform its function, resulting in the disruption of the cytoskeleton and impairment in cellular mobility. Nerve cells (neurons) that do not migrate properly during development form clumps around fluid-filled cavities (ventricles) near the center of the brain, resulting in the signs and symptoms of periventricular heterotopia.

In some cases, mutations result in the substitution of one protein building block (amino acid) for another amino acid in the protein sequence. These mutations may result in the production of a partially functional protein, causing a milder form of the disorder.

Genetics Home Reference provides information about FG syndrome, which is also associated with changes in the FLNA gene.

Where is the FLNA gene located?

Cytogenetic Location: Xq28

Molecular Location on the X chromosome: base pairs 154,348,531 to 154,374,637

The FLNA gene is located on the long (q) arm of the X chromosome at position 28.

The FLNA gene is located on the long (q) arm of the X chromosome at position 28.

More precisely, the FLNA gene is located from base pair 154,348,531 to base pair 154,374,637 on the X chromosome.

See How do geneticists indicate the location of a gene? in the Handbook.

Where can I find additional information about FLNA?

You and your healthcare professional may find the following resources about FLNA helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the FLNA gene or gene products?

  • ABP-280
  • ABPX
  • actin-binding protein 280
  • DKFZp434P031
  • filamin 1
  • filamin A
  • filamin A, alpha (actin binding protein 280)
  • FLN
  • FLN1
  • FLNA_HUMAN

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding FLNA?

actin ; amino acid ; atypical ; blood clotting ; cell ; chromosome ; clotting ; cytoskeleton ; digestive ; dysplasia ; exon ; gastrointestinal ; gene ; neurological ; obstruction ; protein ; protein sequence ; substitution ; syndrome

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

See also Understanding Medical Terminology.

References (11 links)

 

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? in the Handbook.

 
Reviewed: October 2010
Published: October 27, 2014