rs1316686443

Positions:

• chr9-127666293-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP2 PP3_Moderate PP5

The NM_001032221.6(STXBP1):​c.791A>G​(p.Tyr264Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,228 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: STXBP1 NM_001032221.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 9.32

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 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), STXBP1. . Gene score misZ 4.263 (greater than the threshold 3.09). Trascript score misZ 5.8379 (greater than threshold 3.09). GenCC has associacion of gene with intellectual disability, autosomal dominant non-syndromic intellectual disability, Dravet syndrome, undetermined early-onset epileptic encephalopathy, autism spectrum disorder, developmental and epileptic encephalopathy, West syndrome, atypical Rett syndrome, developmental and epileptic encephalopathy, 4.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.924
• PP5: Variant 9-127666293-A-G is Pathogenic according to our data. Variant chr9-127666293-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 495059.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
STXBP1	NM_003165.6	c.791A>G	p.Tyr264Cys	missense_variant	9/20	ENST00000373302.8	NP_003156.1
STXBP1	NM_001032221.6	c.791A>G	p.Tyr264Cys	missense_variant	9/19	ENST00000373299.5	NP_001027392.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
STXBP1	ENST00000373302.8	c.791A>G	p.Tyr264Cys	missense_variant	9/20	1	NM_003165.6	ENSP00000362399.3
STXBP1	ENST00000373299.5	c.791A>G	p.Tyr264Cys	missense_variant	9/19	1	NM_001032221.6	ENSP00000362396.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152228 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152228 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74374

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Developmental and epileptic encephalopathy, 4 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Center of Genomic medicine, Geneva, University Hospital of Geneva

Sep 13, 2017

This de novo missense variant in the STXBP1 gene was identified in a female young patient with epilepsy and development delay. -

Intellectual disability Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Diagnostic Laboratory, Strasbourg University Hospital

Sep 10, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Benign	0.26	.;T;.;T;.;T;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.99	D;.;D;D;D;D;D
M_CAP	Pathogenic	0.70	D
MetaRNN	Pathogenic	0.92	D;D;D;D;D;D;D
MetaSVM	Uncertain	0.71	D
MutationAssessor	Uncertain	2.7	.;.;M;.;.;.;M
PrimateAI	Pathogenic	0.94	D
PROVEAN	Pathogenic	-8.2	.;.;D;.;.;.;D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	.;.;D;.;.;.;D
Sift4G	Pathogenic	0.0	.;.;D;.;.;.;D
Polyphen		1.0	.;.;D;.;.;.;D
Vest4		0.85, 0.87
MutPred		0.62		.;.;Gain of methylation at K265 (P = 0.0204);Gain of methylation at K265 (P = 0.0204);Gain of methylation at K265 (P = 0.0204);.;Gain of methylation at K265 (P = 0.0204);
MVP		0.88
MPC		2.7
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.95
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1316686443; hg19: chr9-130428572;