chr1-42929204-ACT-A

Variant names:

• chr1-42929204-ACT-A
• rs1553155999
• NM_006516.4:c.972+4_972+5delAG

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_006516.4(SLC2A1):​c.972+4_972+5delAG variant causes a splice region, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: SLC2A1 NM_006516.4 splice_region, intron
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.48
• 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 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC2A1	NM_006516.4	c.972+4_972+5delAG		splice_region_variant, intron_variant	Intron 7 of 9	ENST00000426263.10	NP_006507.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC2A1	ENST00000426263.10	c.972+4_972+5delAG		splice_region_variant, intron_variant	Intron 7 of 9	1	NM_006516.4	ENSP00000416293.2

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

GLUT1 deficiency syndrome 1, autosomal recessive Uncertain:1

Aug 15, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 7 of the SLC2A1 gene. It does not directly change the encoded amino acid sequence of the SLC2A1 protein, but it affects a nucleotide within the consensus splice site of the intron. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with SLC2A1-related disease. Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.5
Mutation Taster		=12/88	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.95		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.75		Position offset: 10
DS_DL_spliceai		0.95		Position offset: 6

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

Other links and lift over

dbSNP: rs1553155999; hg19: chr1-43394875;