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Reviewed August 2012
What is the official name of the FMR1 gene?
The official name of this gene is “fragile X mental retardation 1.”
FMR1 is the gene's official symbol. The FMR1 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 FMR1 gene?
The FMR1 gene provides instructions for making a protein called FMRP. This protein is present in many tissues, including the brain, testes, and ovaries. In the brain, it may play a role in the development of connections between nerve cells (synapses), where cell-to-cell communication occurs. The synapses can change and adapt over time in response to experience (a characteristic called synaptic plasticity). FMRP may help regulate synaptic plasticity, which is important for learning and memory. The protein's role in the testes and ovaries is not well understood.
Researchers believe that FMRP acts as a shuttle within cells by transporting molecules called messenger RNA (mRNA), which serve as the genetic blueprint for making proteins. FMRP likely carries mRNA molecules from the nucleus to areas of the cell where proteins are assembled. FMRP also helps control when the instructions in these mRNA molecules are used to build proteins, some of which may be important for functioning of the nerves, testes, or ovaries.
One region of the FMR1 gene contains a particular DNA segment known as a CGG trinucleotide repeat, so called because this segment of three DNA building blocks (nucleotides) is repeated multiple times within the gene. In most people, the number of CGG repeats ranges from fewer than 10 to about 40. This CGG repeat segment is typically interrupted several times by a different three-base sequence, AGG. Having AGG scattered among the CGG triplets appears to help stabilize the long repeated segment.
How are changes in the FMR1 gene related to health conditions?
Where is the FMR1 gene located?
Cytogenetic Location: Xq27.3
Molecular Location on the X chromosome: base pairs 147,911,951 to 147,951,127
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The FMR1 gene is located on the long (q) arm of the X chromosome at position 27.3.
More precisely, the FMR1 gene is located from base pair 147,911,951 to base pair 147,951,127 on the X chromosome.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about FMR1?
You and your healthcare professional may find the following resources about FMR1 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 FMR1 gene or gene products?
See How are genetic conditions and genes named? in the Handbook.
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 FMR1?
acids ; ADHD ; anxiety ; ataxia ; attention deficit hyperactivity disorder ; autism ; base sequence ; cell ; depression ; disabilities ; disability ; DNA ; fertility ; gene ; hormone ; hyperactivity ; infertility ; menopause ; mental retardation ; messenger RNA ; methylation ; mRNA ; mutation ; nervous system ; neuropathy ; nucleus ; ovarian ; peripheral ; peripheral neuropathy ; plasticity ; premutation ; protein ; RNA ; spectrum ; syndrome ; testes ; tremor ; trinucleotide repeat
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (21 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.