Hereditary ataxia
Gene: GRM1
Comment on mode of inheritance: Updated from 'biallelic' to 'both mono- and biallelic'. At least two unrelated cases in literature characterised by AD adult-onset ataxia and supported by functional data, plus additional patients mentioned in Tracy Lester patient cohort.Created: 1 Nov 2022, 4:48 p.m. | Last Modified: 1 Nov 2022, 4:48 p.m.
Panel Version: 1.311
Pathogenic variants in GRM1 have been reported in at least 4 unrelated cases with AR disease (PMID: 22901947; 26308914; 31319223; 36140834) and in 3 unrelated cases with AD disease (PMID: 28886343) - not including additional cases in internal patient cohort mentioned in previous review by Tracy Lester.
Both MOIs are listed in OMIM (MIM# 617691 and MIM# 614831) but only recessive GRM1-related congenital cerebellar ataxia is currently included in G2P.
Biallelic disease is associated with earlier-onset and ID, although some adult patients are reported albeit without indication of the age of onset. On the other hand, the dominant form is a less severe phenotype mainly comprising adult-onset cerebellar ataxia and no cognitive impairment. One juvenile case (presenting ataxic gait and ID) associated with a heterozygous variant was also reported in the same paper but this is not yet sufficient to test heterozygous variants on childhood-onset panel as this may pose a risk of detecting carrier status for an adult-onset condition.Created: 1 Nov 2022, 4:48 p.m. | Last Modified: 1 Nov 2022, 4:48 p.m.
Panel Version: 1.310
Mode of inheritance
BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Phenotypes
Spinocerebellar ataxia 44, OMIM:617691; Spinocerebellar ataxia, autosomal recessive 13, OMIM:614831
Publications
Comment on list classification: Evidence from expert reviewer and OMIMCreated: 4 Feb 2016, 2:09 p.m.
Fine. Good evidence in lit. Mode of inheritance: ARCreated: 24 Nov 2015, 4:57 p.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Spinocerebellar ataxia, autosomal recessive 13
Variants in this GENE are reported as part of current diagnostic practice
Mode of inheritance for gene: GRM1 was changed from BIALLELIC, autosomal or pseudoautosomal to BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Publications for gene: GRM1 were set to
Phenotypes for gene: GRM1 were changed from Spinocerebellar ataxia, autosomal recessive 13 to Spinocerebellar ataxia 44, OMIM:617691; Spinocerebellar ataxia, autosomal recessive 13, OMIM:614831
This gene has been classified as Green List (High Evidence).
This gene has been classified as Green List (High Evidence).
Model of inheritance for gene GRM1 was changed to BIALLELIC, autosomal or pseudoautosomal
GRM1 was added to Hereditary ataxiapanel. Sources: Radboud University Medical Center, Nijmegen,UKGTN
GRM1 was added to Hereditary ataxiapanel. Sources: Radboud University Medical Center, Nijmegen,UKGTN