NM_003165.6:c.1651C>T

Variant names:

• chr9-127682509-C-T
• rs796053373
• NM_003165.6:c.1651C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_003165.6(STXBP1):​c.1651C>T​(p.Arg551Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R551H) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: STXBP1 NM_003165.6 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:13 O:1
• Conservation: PhyloP100: 7.80
• Publications: 26 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: G2P, Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• 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 18 ACMG points.

• PM1: In a hotspot region, there are 13 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 12 uncertain in NM_003165.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-127682510-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 566474.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.97
• PP5: Variant 9-127682509-C-T is Pathogenic according to our data. Variant chr9-127682509-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 207440.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003165.6. 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
	STXBP1	NM_003165.6	MANE Plus Clinical	c.1651C>T	p.Arg551Cys	missense	Exon 18 of 20	NP_003156.1	P61764-2
	STXBP1	NM_001032221.6	MANE Select	c.1651C>T	p.Arg551Cys	missense	Exon 18 of 19	NP_001027392.1	P61764-1
	STXBP1	NM_001374306.2		c.1642C>T	p.Arg548Cys	missense	Exon 18 of 19	NP_001361235.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	STXBP1	ENST00000373302.8	TSL:1 MANE Plus Clinical	c.1651C>T	p.Arg551Cys	missense	Exon 18 of 20	ENSP00000362399.3	P61764-2
	STXBP1	ENST00000373299.5	TSL:1 MANE Select	c.1651C>T	p.Arg551Cys	missense	Exon 18 of 19	ENSP00000362396.2	P61764-1
	STXBP1	ENST00000494254.4	TSL:5	c.1651C>T	p.Arg551Cys	missense	Exon 18 of 19	ENSP00000485397.2	A0A096LP52

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
5	-	-	Developmental and epileptic encephalopathy, 4 (6)
3	-	-	not provided (3)
1	-	-	Developmental and epileptic encephalopathy (1)
1	-	-	Developmental disorder (1)
1	-	-	Infantile epilepsy syndrome (1)
1	-	-	See cases (1)
1	-	-	Seizure (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.29	T
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.82	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	0.83	D
MutationAssessor	Pathogenic	3.2	M
PhyloP100		7.8
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-7.8	D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.95
MutPred		0.82		Loss of methylation at R551 (P = 0.0985)
MVP		0.92
MPC		2.7
ClinPred		1.0	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.94
gMVP		0.99
Mutation Taster		=2/98	disease causing (ClinVar)

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: rs796053373; hg19: chr9-130444788; COSMIC: COSV64813774;