19-7645196-G-A

Variant names:

• chr19-7645196-G-A
• rs140148806
• NM_006949.4:c.1247-1G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_006949.4(STXBP2):​c.1247-1G>A variant causes a splice acceptor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: STXBP2 NM_006949.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.22
• Publications: 0 publications found

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]

STXBP2 Gene-Disease associations (from GenCC):

• familial hemophagocytic lymphohistiocytosis 5

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae)
• hereditary hemophagocytic lymphohistiocytosis

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• microvillus inclusion disease

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

ENSG00000268400 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5, offset of 1, new splice context is: gcccattcccgtcccccaAGtgt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
STXBP2	NM_006949.4	c.1247-1G>A		splice_acceptor_variant, intron_variant	Intron 14 of 18	ENST00000221283.10	NP_008880.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
STXBP2	ENST00000221283.10	c.1247-1G>A		splice_acceptor_variant, intron_variant	Intron 14 of 18	1	NM_006949.4	ENSP00000221283.4
ENSG00000268400	ENST00000698368.1	n.*1350-1G>A		splice_acceptor_variant, intron_variant	Intron 16 of 19			ENSP00000513686.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1406964 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 694716

African (AFR) AF: 0.00 AC: 0 AN: 32010

American (AMR) AF: 0.00 AC: 0 AN: 36952

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25294

East Asian (EAS) AF: 0.00 AC: 0 AN: 36486

South Asian (SAS) AF: 0.00 AC: 0 AN: 79978

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49614

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5710

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1082616

Other (OTH) AF: 0.00 AC: 0 AN: 58304

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.15
CADD	Pathogenic	34
DANN	Uncertain	1.0
DEOGEN2	Benign	0.0	.;.;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.82
LIST_S2	Benign	0.0	.;.;.
MetaRNN	Benign	0.0	.;.;.
MutationAssessor	Benign	0.0	.;.;.
PhyloP100		9.2
PROVEAN	Benign	0.0	.;.;.
Sift	Pathogenic	0.0	.;.;.
Sift4G	Pathogenic	0.0	.;.;.
Vest4		0.0
GERP RS		4.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.60		Position offset: 2
DS_AL_spliceai		1.0		Position offset: 1

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

Other links and lift over

dbSNP: rs140148806; hg19: chr19-7710082;