9-127690839-T-A

Position:

• chr9-127690839-T-A

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM2 PP2 BP4_Strong

The NM_001032221.6(STXBP1):​c.1767T>A​(p.Asp589Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,770 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: STXBP1 NM_001032221.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.706

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]

PTRH1 (HGNC:27039): (peptidyl-tRNA hydrolase 1 homolog) Enables RNA binding activity. [provided by Alliance of Genome Resources, Apr 2022]

ENSG00000279571 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -1 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.06653845).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
STXBP1	NM_001032221.6	c.1767T>A	p.Asp589Glu	missense_variant	19/19	ENST00000373299.5	NP_001027392.1
STXBP1	NM_003165.6	c.*81T>A		3_prime_UTR_variant	20/20	ENST00000373302.8	NP_003156.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
STXBP1	ENST00000373299.5	c.1767T>A	p.Asp589Glu	missense_variant	19/19	1	NM_001032221.6	ENSP00000362396.2
STXBP1	ENST00000373302.8	c.*81T>A		3_prime_UTR_variant	20/20	1	NM_003165.6	ENSP00000362399.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461770 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 727174

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Nov 14, 2019

Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes splice predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.064
BayesDel_addAF	Benign	-0.046	T
BayesDel_noAF	Benign	-0.30
CADD	Benign	16
DANN	Uncertain	0.98
DEOGEN2	Benign	0.0055	T;T;T
Eigen	Benign	-0.70
Eigen_PC	Benign	-0.50
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Benign	0.52	.;T;T
M_CAP	Benign	0.036	D
MetaRNN	Benign	0.067	T;T;T
MetaSVM	Benign	-0.90	T
MutationAssessor	Benign	0.90	.;.;L
PROVEAN	Benign	0.10	.;.;N
REVEL	Benign	0.23
Sift	Benign	1.0	.;.;T
Sift4G	Benign	1.0	.;.;T
Polyphen		0.0040	.;.;B
Vest4		0.064
MutPred		0.23		.;.;Loss of loop (P = 0.0374);
MVP		0.76
ClinPred		0.29	T
GERP RS		1.4
Varity_R		0.034

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

Publications

LitVar

Other links and lift over

dbSNP: rs974441233; hg19: chr9-130453118;