chr1-42929683-G-C

Variant names:

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

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), 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: 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 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.
• 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

Selected	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

Ensembl Transcripts

Selected	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
	SLC2A1	ENST00000674765.1		c.777C>G	p.Ile259Met	missense	Exon 6 of 9	ENSP00000501811.1
	SLC2A1	ENST00000630287.2	TSL:5	n.*92C>G		non_coding_transcript_exon	Exon 5 of 9	ENSP00000486694.1

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
Polyphen		0.099	B
Vest4		0.41
MutPred		0.45		Gain of disorder (P = 0.0209)
MVP		0.59
MPC		2.0
ClinPred		0.75	D
GERP RS		3.2
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

Other links and lift over

dbSNP: rs78388808; hg19: chr1-43395354;