rs758554274

chr19-7647487-G-Achr19-7647487-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_006949.4(STXBP2):c.1672G>A(p.Glu558Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000255 in 1,604,936 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E558D) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000025 (0 hom.)
• Consequence: STXBP2 NM_006949.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.81

Genes affected

STXBP2 (HGNC:11445): (syntaxin binding protein 2) This gene encodes a member of the STXBP/unc-18/SEC1 family. The encoded protein is involved in intracellular trafficking, control of SNARE (soluble NSF attachment protein receptor) complex assembly, and the release of cytotoxic granules by natural killer cells. Mutations in this gene are associated with familial hemophagocytic lymphohistiocytosis. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene. [provided by RefSeq, Jan 2013]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10695553).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
STXBP2	NM_006949.4	c.1672G>A	p.Glu558Lys	missense_variant	18/19	ENST00000221283.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
STXBP2	ENST00000221283.10	c.1672G>A	p.Glu558Lys	missense_variant	18/19	1	NM_006949.4	P4

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152190 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000588

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000869 AC: 2 AN: 230252 Hom.: 0 AF XY: 0.00000798 AC XY: 1 AN XY: 125360

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000307

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000342

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000248 AC: 36 AN: 1452746 Hom.: 0 Cov.: 76 AF XY: 0.0000249 AC XY: 18 AN XY: 722242

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000231

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000256

Gnomad4 SAS exome AF: 0.0000234

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000280

Gnomad4 OTH exome AF: 0.0000167

GnomAD4 genome AF: 0.0000329 AC: 5 AN: 152190 Hom.: 0 Cov.: 33 AF XY: 0.0000538 AC XY: 4 AN XY: 74340

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000588

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000127 Hom.: 0

Bravo AF: 0.0000189

ExAC AF: 0.0000165 AC: 2

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial hemophagocytic lymphohistiocytosis 5 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Jun 20, 2022	This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 558 of the STXBP2 protein (p.Glu558Lys). This variant is present in population databases (rs758554274, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with STXBP2-related conditions. ClinVar contains an entry for this variant (Variation ID: 330563). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.091	T
BayesDel_noAF	Benign	-0.27
Cadd	Benign	22
Dann	Benign	0.60
Eigen	Benign	-0.65
Eigen_PC	Benign	-0.45
FATHMM_MKL	Uncertain	0.78	D
LIST_S2	Uncertain	0.96	D;D;D;D
M_CAP	Benign	0.020	T
MetaRNN	Benign	0.11	T;T;T;T
MetaSVM	Benign	-0.87	T
MutationTaster	Benign	0.68	D;D;D
PrimateAI	Benign	0.38	T
PROVEAN	Benign	1.8	N;N;N;.
REVEL	Benign	0.17
Sift	Benign	1.0	T;T;T;.
Sift4G	Benign	1.0	T;T;T;T
Polyphen		0.0	.;B;B;.
Vest4		0.34
MVP		0.56
MPC		0.28
ClinPred		0.45	T
GERP RS		3.1
Varity_R		0.17
gMVP		0.49

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs758554274; hg19: chr19-7712373; COSMIC: COSV55404331; COSMIC: COSV55404331;