rs387907312

Positions:

• chr1-42929918-G-A

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_006516.4(SLC2A1):​c.634C>T​(p.Arg212Cys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R212H) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SLC2A1 NM_006516.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 6.77

Genes affected

SLC2A1 (HGNC:11005): (solute carrier family 2 member 1) This gene encodes a major glucose transporter in the mammalian blood-brain barrier. The encoded protein is found primarily in the cell membrane and on the cell surface, where it can also function as a receptor for human T-cell leukemia virus (HTLV) I and II. Mutations in this gene have been found in a family with paroxysmal exertion-induced dyskinesia. [provided by RefSeq, Apr 2013]

ACMG classification

Verdict is Pathogenic. Variant got 19 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 9 uncertain in NM_006516.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-42929917-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 265386.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SLC2A1. . Gene score misZ: 2.9256 (greater than the threshold 3.09). Trascript score misZ: 4.6729 (greater than threshold 3.09). The gene has 98 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. GenCC has associacion of the gene with childhood absence epilepsy, dystonia 9, epilepsy, idiopathic generalized, susceptibility to, 12, GLUT1 deficiency syndrome, myoclonic-astatic epilepsy, childhood onset GLUT1 deficiency syndrome 2, hereditary cryohydrocytosis with reduced stomatin, encephalopathy due to GLUT1 deficiency.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant 1-42929918-G-A is Pathogenic according to our data. Variant chr1-42929918-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 37300.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SLC2A1	NM_006516.4	c.634C>T	p.Arg212Cys	missense_variant	5/10	ENST00000426263.10	NP_006507.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SLC2A1	ENST00000426263.10	c.634C>T	p.Arg212Cys	missense_variant	5/10	1	NM_006516.4	ENSP00000416293.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Apr 06, 2016	The R212C variant in the SLC2A1 gene has been reported previously in an individual with seizures, mild intellectual disability, and biochemical findings consistent with Glut1-DS (Leen et al., 2010). The R212C variant has also been reported in multiple affected individuals in a large family with paroxysmal exercise-induced dyskinesia (Weber et al., 2011). Functional studies suggest that R212C results in reduced glucose uptake (Weber et al., 2011). It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The R212C variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species, and a different missense variant in the same residue (R212H) as well as missense variants in nearby residues (E209D, L215F) have been reported in the Human Gene Mutation Database in association with SLC2A1-related disorders (Stenson et al., 2014), supporting the functional importance of this region of the protein. -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Feb 01, 2022	- -

Dystonia 9 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Sep 06, 2011

- -

Encephalopathy due to GLUT1 deficiency Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

GLUT1 deficiency syndrome 1, autosomal recessive Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 02, 2021

For these reasons, this variant has been classified as Pathogenic. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SLC2A1 protein function. This variant has been observed in individual(s )with fasting CSF/blood glucose ratios <0.45, findings that are highly specific for glucose transporter-1 deficiency syndrome (PMID: 20129935, 22622956), and in an individual affected with symptoms of glucose transporter-1 deficiency syndrome (PMID: 26982753). This variant has also been observed to segregate with paroxysmal choreoathetosis/spasticity in a family (PMID: 21832227). ClinVar contains an entry for this variant (Variation ID: 37300). This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with cysteine at codon 212 of the SLC2A1 protein (p.Arg212Cys). The arginine residue is highly conserved and there is a large physicochemical difference between arginine and cysteine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.92	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.65	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Pathogenic	4.6	H
PrimateAI	Pathogenic	0.80	D
PROVEAN	Pathogenic	-7.5	D
REVEL	Pathogenic	0.86
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.96		Loss of disorder (P = 0.0827);
MVP		0.97
MPC		2.3
ClinPred		1.0	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.94
gMVP		0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs387907312; hg19: chr1-43395589;