1-42930724-C-G

Variant names:

• chr1-42930724-C-G
• rs1057517822
• NM_006516.4:c.418G>C

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PS1 PM1 PM2 PM5 PP2 PP3 PP5_Moderate

The NM_006516.4(SLC2A1):​c.418G>C​(p.Val140Leu) 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. Variant has been reported in ClinVar as Pathogenic (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V140M) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SLC2A1 NM_006516.4 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.85
• Publications: 4 publications found

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]

SLC2A1 Gene-Disease associations (from GenCC):

• encephalopathy due to GLUT1 deficiency

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet
• GLUT1 deficiency syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• childhood onset GLUT1 deficiency syndrome 2

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
• dystonia 9

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• epilepsy, idiopathic generalized, susceptibility to, 12

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• childhood absence epilepsy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hereditary cryohydrocytosis with reduced stomatin

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• myoclonic-astatic epilepsy

  Inheritance: Unknown Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 14 ACMG points.

• PS1: Transcript NM_006516.4 (SLC2A1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM1: In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 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 chr1-42930724-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 372507.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the SLC2A1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 98 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: 2.9256 (below the threshold of 3.09). Trascript score misZ: 4.6729 (above the threshold of 3.09). GenCC associations: The gene is linked to epilepsy, idiopathic generalized, susceptibility to, 12, GLUT1 deficiency syndrome, encephalopathy due to GLUT1 deficiency, dystonia 9, hereditary cryohydrocytosis with reduced stomatin, childhood onset GLUT1 deficiency syndrome 2, childhood absence epilepsy, myoclonic-astatic epilepsy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.799
• PP5: Variant 1-42930724-C-G is Pathogenic according to our data. Variant chr1-42930724-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 538677.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC2A1	NM_006516.4	c.418G>C	p.Val140Leu	missense_variant	Exon 4 of 10	ENST00000426263.10	NP_006507.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC2A1	ENST00000426263.10	c.418G>C	p.Val140Leu	missense_variant	Exon 4 of 10	1	NM_006516.4	ENSP00000416293.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

GLUT1 deficiency syndrome 1, autosomal recessive Pathogenic:1

Feb 08, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 140 of the SLC2A1 protein (p.Val140Leu). For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Val140 amino acid residue in SLC2A1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 18577546, 29356177). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. ClinVar contains an entry for this variant (Variation ID: 538677). This missense change has been observed in individual(s) with SLC2A1-related conditions (PMID: 31273778; Invitae). This variant is not present in population databases (gnomAD no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.84
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D;.
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.29	D
MetaRNN	Pathogenic	0.80	D;D
MetaSVM	Uncertain	0.33	D
MutationAssessor	Uncertain	2.5	M;.
PhyloP100		5.8
PrimateAI	Uncertain	0.79	T
PROVEAN	Uncertain	-2.4	N;N
REVEL	Pathogenic	0.78
Sift	Uncertain	0.0040	D;T
Sift4G	Benign	0.086	T;T
Polyphen		0.98	D;.
Vest4		0.82
MutPred		0.68		Loss of catalytic residue at V140 (P = 0.3193);.;
MVP		0.88
MPC		2.0
ClinPred		0.96	D
GERP RS		5.5
Varity_R		0.91
gMVP		0.87
Mutation Taster		=5/95	disease causing

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

Other links and lift over

dbSNP: rs1057517822; hg19: chr1-43396395;