Likely inborn error of metabolism - targeted testing not possible
Gene: FXNComment on phenotypes: Friedreich ataxia, 229300;Friedreich ataxia with retained reflexes, 229300;Hereditary ataxia;Defective Fe-S/lipoic acid biosynthesis (Mitochondrial respiratory chain disorders (caused by nuclear variants only))Created: 11 May 2021, 2:42 p.m. | Last Modified: 11 May 2021, 2:42 p.m.
Panel Version: 2.132
Comment on list classification: Associated with phenotype in OMIM and not in Gen2Phen. At least 9 variants identified in unrelated cases.
FXN is rated Red on the mitochondrial panels on the recommendation of the GMS mitochondrial specialist test group, including by Carl Fratter (Oxford University Hospitals NHS Trust). As it is associated with Friedreich’s ataxia, which is technically a mitochondrial disorder, but the phenotype is different to other mitochondrial conditions.Created: 1 Aug 2019, 1:06 p.m. | Last Modified: 1 Aug 2019, 1:06 p.m.
Panel Version: 1.72
Although this encodes a mitochondrial protein, this mainly results in ataxiaCreated: 19 Jun 2019, 12:26 p.m.
Phenotypes
Friedreich ataxia, 229300
Red - Friedreich ataxia - not considered a primary mitochondrial disorderCreated: 11 Jun 2019, 3:59 p.m.
Phenotypes
Friedreich ataxia, 229300
Comment on list classification: Promoted from red to green based on the provided expert reviews. FXN is associated with a phenotype in OMIM but not in Gene2Phenotype. There are >3 unrelated cases of patients with variants in this gene; therefore, there is sufficient evidence to support the promotion of this gene to green status.Created: 2 May 2019, 9:50 a.m.
The literature which considers FA to be a mitochondrial disorder is extensive. Note trinucleotide expansion accounts for majority of mutations.Created: 29 Aug 2018, 7:30 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Freidrich's ataxia
Publications
Variants in this GENE are reported as part of current diagnostic practice
Comment when marking as ready: Asked second reviewer - should remain red for now.Created: 7 Mar 2016, 5:56 p.m.
Tag nucleotide-repeat-expansion tag was added to gene: FXN.
Phenotypes for gene: FXN were changed from Friedreich ataxia, 229300; Friedreich ataxia with retained reflexes, 229300; Hereditary ataxia; Defective Fe-S/lipoic acid biosynthesis (Mitochondrial respiratory chain disorders (caused by nuclear variants only)) to Friedreich ataxia OMIM:229300; Friedreich ataxia with retained reflexes OMIM:229300; Friedreich ataxia 1 MONDO:0100340
Gene: fxn has been classified as Green List (High Evidence).
Source NHS GMS was added to FXN. Source London North GLH was added to FXN.
Phenotypes for gene: FXN were changed from Friedreich ataxia, 229300Friedreich ataxia with retained reflexes, 229300; Hereditary ataxia; Defective Fe-S/lipoic acid biosynthesis (Mitochondrial respiratory chain disorders (caused by nuclear variants only)) to Friedreich ataxia, 229300; Friedreich ataxia with retained reflexes, 229300; Hereditary ataxia; Defective Fe-S/lipoic acid biosynthesis (Mitochondrial respiratory chain disorders (caused by nuclear variants only))
Sarah Leigh: Associated with relevant pheno
Added phenotypes Friedreich ataxia, 229300Friedreich ataxia with retained reflexes, 229300 for gene: FXN
gene: FXN was added gene: FXN was added to Inborn errors of metabolism. Sources: Expert Review Amber Mode of inheritance for gene: FXN was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: FXN were set to 27604308 Phenotypes for gene: FXN were set to Hereditary ataxia; Defective Fe-S/lipoic acid biosynthesis (Mitochondrial respiratory chain disorders (caused by nuclear variants only))