16-30992838-C-T

Variant names:

• chr16-30992838-C-T
• NM_052874.5:c.850G>A

Variant summary

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

The NM_052874.5(STX1B):​c.850G>A​(p.Gly284Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: STX1B NM_052874.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.02

Genes affected

STX1B (HGNC:18539): (syntaxin 1B) The protein encoded by this gene belongs to a family of proteins thought to play a role in the exocytosis of synaptic vesicles. Vesicle exocytosis releases vesicular contents and is important to various cellular functions. For instance, the secretion of transmitters from neurons plays an important role in synaptic transmission. After exocytosis, the membrane and proteins from the vesicle are retrieved from the plasma membrane through the process of endocytosis. Mutations in this gene have been identified as one cause of fever-associated epilepsy syndromes. A possible link between this gene and Parkinson's disease has also been suggested. [provided by RefSeq, Jan 2015]

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 rank	MANE	Protein	UniProt
STX1B	NM_052874.5	c.850G>A	p.Gly284Arg	missense_variant	Exon 10 of 10	ENST00000215095.11	NP_443106.1
STX1B	XM_017022893.2	c.832G>A	p.Gly278Arg	missense_variant	Exon 10 of 10		XP_016878382.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
STX1B	ENST00000215095.11	c.850G>A	p.Gly284Arg	missense_variant	Exon 10 of 10	1	NM_052874.5	ENSP00000215095.5
STX1B	ENST00000565419.2	c.*244G>A		downstream_gene_variant		2		ENSP00000455899.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Generalized epilepsy with febrile seizures plus, type 9 Uncertain:1

Apr 23, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 284 of the STX1B protein (p.Gly284Arg). 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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 1487125). This variant has not been reported in the literature in individuals affected with STX1B-related conditions. This variant is not present in population databases (gnomAD no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Uncertain	0.076	D
BayesDel_noAF	Benign	-0.13
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.33	T
Eigen	Uncertain	0.52
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.83	D
LIST_S2	Uncertain	0.88	D
M_CAP	Benign	0.026	D
MetaRNN	Uncertain	0.60	D
MetaSVM	Benign	-0.85	T
MutationAssessor	Uncertain	2.6	M
PrimateAI	Pathogenic	0.79	T
PROVEAN	Benign	-1.0	N
REVEL	Benign	0.21
Sift	Benign	0.26	T
Sift4G	Benign	0.47	T
Polyphen		1.0	D
Vest4		0.63
MutPred		0.40		Gain of methylation at G284 (P = 0.0296);
MVP		0.31
MPC		2.6
ClinPred		0.85	D
GERP RS		4.6
Varity_R		0.32
gMVP		0.87

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr16-31004159;