Genes in panel

Ataxia and cerebellar anomalies - narrow panel

Gene: SLC52A2

Green List (high evidence)

SLC52A2 (solute carrier family 52 member 2)
EnsemblGeneIds (GRCh38): ENSG00000185803
EnsemblGeneIds (GRCh37): ENSG00000185803
OMIM: 607882, Gene2Phenotype
SLC52A2 is in 18 panels

3 reviews

Eleanor Williams (Genomics England Curator)

Green List (high evidence)

The rating of this gene has been updated to green following NHS Genomic Medicine Service approval.
Created: 11 Oct 2023, 10:01 a.m. | Last Modified: 11 Oct 2023, 10:01 a.m.
Panel Version: 4.37

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Achchuthan Shanmugasundram (Genomics England Curator)

Green List (high evidence)

Comment on classification of this gene: The rating for this gene should be added as GREEN, as this gene has been implicated in ataxia, as identified from biallelic loss-of-function variants from >20 unrelated individuals/ families from multiple ethnicities and supported by results from functional studies. Several of these patients treated with oral riboflavin responded well to the treatment.

Unrelated individuals carrying homozygous variants (e.g. c.916G>A/ p.Gly306Arg) and compound heterozygous variants (e.g. c.368T>C/ p.Leu123Pro & c.1016T>C/ p.Leu339Pro) were reported with Brown-Vialetto-Van Laere syndrome-2. According to report from Foley et al (2014), patients were presented with ataxia (9 out of 18 patients), hearing loss (all 18 patients), limb/ muscle weakness (17 patients), optic atrophy/ impaired vision (14 of 15 patients), tongue fasciculations (11 of 18 patients) and axonal sensorimotor neuropathy (all 18 patients). The onset of ataxia ranged from 1.5 to 8 years of age and some of these patients were confined to a wheelchair in their childhood (ranging from 1.5 to 8 years old). Respiratory insufficiency developed in 13 patients (PMID:24253200). One patient from this study and patient from Ciccolella et al (2012) bearing compound heterozygous variants were hospitalized for respiratory failure and died at 3-4 years of age (PMID:24253200; PMID:23243084).

A report on an eight year old patient with already identified homozygous variant (c.916G>A/ p.Gly306Arg) was presented with progressive ataxia since the age of 2.5 years and cerebellar atrophy and peripheral polyneuropathy despite the absence of other common symptoms of Brown-Vialetto-Van Laere syndrome including motor neuropathy, bulbar palsy, optic atrophy, and sensorineural hearing loss (PMID:30377535). Another two year old boy was presented with severe macrocytic anaemia necessitating multiple blood transfusions and intermittent neutropenia and he subsequently developed ataxia and dysarthria (PMID:32909658).

A recent review and statistical analysis by Zhou et al reports data of 62 BVVL type 2 patients from 43 different families, of which 40 patients had homozygous and 22 patients had compound heterozygous variants. A total of 32 variants have been reported to date, with the most common being missense variants. The symptoms of BVVL type 2 appear at the earliest shortly after birth and at the latest at 10 years of age. The most common symptoms are hearing loss (83.9%), muscle weakness (80.6%), visual impairment (64.5%), and ataxia (61.3%). In addition, this study also suggests that homozygous pattern was more likely to present with ataxia as the first symptom in patients with missense mutations (p < 0.05), while compound heterozygous pattern was more likely to develop respiratory insufficiency during the course of disease (p < 0.001) (PMID:36186484).

Transfection and overexpression of SLC52A2 gene containing mutant alleles in HEK293 showed that the riboflavin uptake activity was abolished in certain mutants and moderately reduced in others. In addition, the expression levels of mutants were decreased (in correlation with the reduction in activity) with the exception of only one mutant tested (PMID:22864630; PMID:24253200).
Created: 11 Dec 2022, 10:45 a.m. | Last Modified: 11 Dec 2022, 10:45 a.m.
Panel Version: 3.11

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Brown-Vialetto-Van Laere syndrome 2, MIM# 614707, MONDO:0013867; Cerebellar ataxia, MONDO:0000437

Publications

Zornitza Stark (Australian Genomics)

Green List (high evidence)

Generally presents with a range of neuropathies but ataxia described. Treatable condition.
Sources: Expert list
Created: 13 Sep 2020, 6:31 a.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Brown-Vialetto-Van Laere syndrome 2, MIM# 614707

Publications

Variants in this GENE are reported as part of current diagnostic practice

History Filter Activity

11 Oct 2023, Gel status: 3

Removed Tag

Achchuthan Shanmugasundram (Genomics England Curator)

Tag Q4_22_promote_green was removed from gene: SLC52A2.

11 Oct 2023, Gel status: 3

Added New Source, Added New Source, Status Update

Achchuthan Shanmugasundram (Genomics England Curator)

Source Expert Review Green was added to SLC52A2. Source NHS GMS was added to SLC52A2. Rating Changed from Amber List (moderate evidence) to Green List (high evidence)

11 Dec 2022, Gel status: 2

Added Tag, Added Tag

Achchuthan Shanmugasundram (Genomics England Curator)

Tag treatable tag was added to gene: SLC52A2. Tag Q4_22_promote_green tag was added to gene: SLC52A2.

11 Dec 2022, Gel status: 2

Set Phenotypes

Achchuthan Shanmugasundram (Genomics England Curator)

Phenotypes for gene: SLC52A2 were changed from Brown-Vialetto-Van Laere syndrome 2, MIM# 614707 to Brown-Vialetto-Van Laere syndrome 2, MIM# 614707, MONDO:0013867; Cerebellar ataxia, MONDO:0000437

11 Dec 2022, Gel status: 2

Set publications

Achchuthan Shanmugasundram (Genomics England Curator)

Publications for gene: SLC52A2 were set to 30377535

11 Dec 2022, Gel status: 2

Entity classified by Genomics England curator

Achchuthan Shanmugasundram (Genomics England Curator)

Gene: slc52a2 has been classified as Amber List (Moderate Evidence).

13 Sep 2020, Gel status: 0

Created, Added New Source, Set mode of inheritance, Set publications, Set Phenotypes

Zornitza Stark (Australian Genomics)

gene: SLC52A2 was added gene: SLC52A2 was added to Ataxia and cerebellar anomalies - narrow panel. Sources: Expert list Mode of inheritance for gene: SLC52A2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: SLC52A2 were set to 30377535 Phenotypes for gene: SLC52A2 were set to Brown-Vialetto-Van Laere syndrome 2, MIM# 614707 Review for gene: SLC52A2 was set to GREEN gene: SLC52A2 was marked as current diagnostic