Repeat Disorders
STR: FXTASGRCh37 Position: 146993569-146993628
GRCh38 Position: 147912051-147912110
Repeated Sequence: CGG
Normal Number of Repeats: < 44
Pathogenic Number of Repeats: = or > 55
FMR1 (fragile X mental retardation 1)
EnsemblGeneIds (GRCh38): ENSG00000102081
EnsemblGeneIds (GRCh37): ENSG00000102081
OMIM: 309550, Gene2Phenotype
FMR1 is in 0 panels
1 review
Bryony Thompson (Royal Melbourne Hospital)
HGVS nomenclature - NM_002024.5:c.-129_-127CGG[X]
RNA-mediated toxicity may result in the FXTAS phenotype, whereas loss of function through methylation silencing of FMR1 is associated with the FXS phenotype.
Intermediate (grey zone, inconclusive, borderline): ~45 to ~54 repeats
Premutation - risk of FXTAS: ~55 to ~200 repeats
Full mutation - fragile X syndrome (FXS): >200 repeats
Sources: Expert listCreated: 26 Aug 2021, 9:55 a.m.
Mode of inheritance
X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)
Phenotypes
Fragile X tremor/ataxia syndrome MIM#300623
Publications
Clinically RelevantInterruptions in the repeated sequence are reported as part of standard diagnostic practise
Details
- Name
- FXTAS
- Chromosome
- X
- GRCh37 Coordinates
- 146993569-146993628
- GRCh38 Coordinates
- 147912051-147912110
- Repeated Sequence
- CGG
- Normal Number of Repeats: <
- 44
- Pathogenic Number of Repeats: = or >
- 55
- Mode of Inheritance
- X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)
- Sources
-
- Expert Review Green
- Expert list
- Phenotypes
-
- Fragile X tremor/ataxia syndrome MIM#300623
- Tags
- OMIM
- 309550
- Clinvar variants
- Variants in FMR1
- Penetrance
- None
- Publications
History Filter Activity
Added Tag
Zornitza Stark (Victorian Clinical Genetics Services; Australian Genomics)Tag adult-onset tag was added to STR: FXTAS.
Entity classified by Genomics England curator
Bryony Thompson (Royal Melbourne Hospital)Str: fxtas has been classified as Green List (High Evidence).
Entity classified by Genomics England curator
Bryony Thompson (Royal Melbourne Hospital)Str: fxtas has been classified as Green List (High Evidence).
Created, Added New Source, Set mode of inheritance, Set publications, Set Phenotypes
Bryony Thompson (Royal Melbourne Hospital)STR: FXTAS was added STR: FXTAS was added to Repeat Disorders. Sources: Expert list Mode of inheritance for STR: FXTAS was set to X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males) Publications for STR: FXTAS were set to 23765048; 25227148; 11445641 Phenotypes for STR: FXTAS were set to Fragile X tremor/ataxia syndrome MIM#300623 Review for STR: FXTAS was set to GREEN STR: FXTAS was marked as clinically relevant