9-127612428-G-CT

Variant names:

• chr9-127612428-G-CT
• rs2132275633
• NM_003165.6:c.25delGinsCT

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_001032221.6(STXBP1):​c.25delGinsCT​(p.Val9LeufsTer9) variant causes a frameshift, missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V9G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 30)
• Consequence: STXBP1 NM_001032221.6 frameshift, missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 0.00300
• Publications: 0 publications found

Genes affected

STXBP1 (HGNC:11444): (syntaxin binding protein 1) This gene encodes a syntaxin-binding protein. The encoded protein appears to play a role in release of neurotransmitters via regulation of syntaxin, a transmembrane attachment protein receptor. Mutations in this gene have been associated with infantile epileptic encephalopathy-4. Alternatively spliced transcript variants have been described. [provided by RefSeq, Feb 2010]

STXBP1 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 4

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• genetic developmental and epileptic encephalopathy

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• atypical Rett syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal dominant non-syndromic intellectual disability

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Dravet syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• infantile spasms

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• undetermined early-onset epileptic encephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autism spectrum disorder

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• intellectual disability

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 307 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-127612428-G-CT is Pathogenic according to our data. Variant chr9-127612428-G-CT is described in ClinVar as [Pathogenic]. Clinvar id is 1202628.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
STXBP1	NM_003165.6	c.25delGinsCT	p.Val9LeufsTer9	frameshift_variant, missense_variant	Exon 1 of 20	ENST00000373302.8	NP_003156.1
STXBP1	NM_001032221.6	c.25delGinsCT	p.Val9LeufsTer9	frameshift_variant, missense_variant	Exon 1 of 19	ENST00000373299.5	NP_001027392.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
STXBP1	ENST00000373302.8	c.25delGinsCT	p.Val9LeufsTer9	frameshift_variant, missense_variant	Exon 1 of 20	1	NM_003165.6	ENSP00000362399.3
STXBP1	ENST00000373299.5	c.25delGinsCT	p.Val9LeufsTer9	frameshift_variant, missense_variant	Exon 1 of 19	1	NM_001032221.6	ENSP00000362396.2

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 30

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Developmental and epileptic encephalopathy, 4 Pathogenic:1

-

Génétique des Maladies du Développement, Hospices Civils de Lyon

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.0030

Splicing

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

Other links and lift over

dbSNP: rs2132275633; hg19: chr9-130374707;