FMR-1 gene | definition of FMR-1 gene by Medical dictionary
A gene found on the X chromosome. Its exact purpose is unknown, but it is suspected that the gene plays a role in brain development.
References in periodicals archive
Affected individuals have >200 CGG repeats and are classified as having a full mutation (FM) which is associated with hypermethylation of an upstream gene promoter region (CpG island) and silencing of FMR-1 gene
transcription which results in the absence of the gene product, fragile X mental retardation protein (FMRP).
Absence of expression of the FMR-1 gene
in fragile X syndrome.
Normal variation in size of the FMR-1 gene
is not associated with variation in intellectual performance.
These premutations are unstable and can expand in size when passed from mother to child If the premutation expands to the size of a full mutation, the FMR-1 gene
"turns off" and does not work properly.
In these, the affected fmr-1 gene
had 57, 168, 182, 207, 266, or 285 repeats.