NM_006516.4:c.777C>G

Variant names:

• chr1-42929683-G-C
• rs78388808
• NM_006516.4:c.777C>G
• SLC2A1 p.Ile259Met

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_006516.4(SLC2A1):​c.777C>G​(p.Ile259Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,508 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I259L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SLC2A1 NM_006516.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.622
• Publications: 0 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), Orphanet, G2P
• GLUT1 deficiency syndrome

  Inheritance: AD, SD Classification: DEFINITIVE, STRONG Submitted by: ClinGen, PanelApp Australia
• childhood onset GLUT1 deficiency syndrome 2

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

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp
• 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: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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 encephalopathy due to GLUT1 deficiency, GLUT1 deficiency syndrome, childhood onset GLUT1 deficiency syndrome 2, myoclonic-astatic epilepsy, hereditary cryohydrocytosis with reduced stomatin, dystonia 9, childhood absence epilepsy, epilepsy, idiopathic generalized, susceptibility to, 12.
• BP4: Computational evidence support a benign effect (MetaRNN=0.3169716).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006516.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SLC2A1	NM_006516.4	MANE Select	c.777C>G	p.Ile259Met	missense	Exon 6 of 10	NP_006507.2	P11166

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SLC2A1	ENST00000426263.10	TSL:1 MANE Select	c.777C>G	p.Ile259Met	missense	Exon 6 of 10	ENSP00000416293.2	P11166
	SLC2A1	ENST00000889577.1		c.774C>G	p.Ile258Met	missense	Exon 6 of 10	ENSP00000559636.1
	SLC2A1	ENST00000958848.1		c.777C>G	p.Ile259Met	missense	Exon 6 of 10	ENSP00000628907.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461508 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727056

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53152

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111904

Other (OTH) AF: 0.00 AC: 0 AN: 60386

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Uncertain	0.027	T
BayesDel_noAF	Benign	-0.20
CADD	Benign	22
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.68	D
Eigen	Benign	-0.067
Eigen_PC	Benign	0.060
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Uncertain	0.87	D
M_CAP	Benign	0.040	D
MetaRNN	Benign	0.32	T
MetaSVM	Benign	-0.61	T
MutationAssessor	Benign	1.3	L
PhyloP100		0.62
PrimateAI	Uncertain	0.61	T
PROVEAN	Uncertain	-2.5	N
REVEL	Uncertain	0.39
Sift	Benign	0.20	T
Sift4G	Benign	0.17	T
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		3.0
Varity_R		0.61
gMVP		0.67
Mutation Taster		=39/61	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs78388808;

hg19: chr1-43395354;