chr17-9568370-C-T

Position:

• chr17-9568370-C-T

Variant summary

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

The NM_004853.3(STX8):​c.117+1G>A variant causes a splice donor change. 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. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: STX8 NM_004853.3 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.13

Genes affected

STX8 (HGNC:11443): (syntaxin 8) The gene is a member of the syntaxin family. The encoded protein is involved in protein trafficking from early to late endosomes via vesicle fusion and exocytosis. A related pseudogene has been identified on chromosome 12. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
STX8	NM_004853.3	c.117+1G>A		splice_donor_variant		ENST00000306357.9	NP_004844.1
STX8	XM_011524079.2	c.158+1G>A		splice_donor_variant			XP_011522381.1
STX8	NR_033656.2	n.129+1G>A		splice_donor_variant, non_coding_transcript_variant
STX8	XR_934120.3	n.129+1G>A		splice_donor_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
STX8	ENST00000306357.9	c.117+1G>A		splice_donor_variant		1	NM_004853.3	ENSP00000305255	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 33

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

Clinical Genomics Laboratory, Washington University in St. Louis

Aug 15, 2023

The STX8 c.117+1G>A variant, to our knowledge, has not been reported in the medical literature and is absent from the general population (gnomAD v.2.1.1), indicating it is not a common variant. This variant occurs within the canonical splice donor site, which is predicted to cause skipping of the exon, leading to an out of frame transcript. However, this gene is not constrained for loss of function (gnomAD browser), so the effect of a loss of STX8 function is unknown. Due to limited information, the clinical significance of this variant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Uncertain	0.92	D
MutationTaster	Benign	1.0	D;D;D
GERP RS		5.6

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.86
SpliceAI score (max)		0.92		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.37		Position offset: 18
DS_DL_spliceai		0.92		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs1436403910; hg19: chr17-9471687;