9-127684454-G-A

Variant names:

• chr9-127684454-G-A
• rs749807465
• NM_003165.6:c.1789G>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4 BP6

The NM_003165.6(STXBP1):​c.1789G>A​(p.Asp597Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,774 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: STXBP1 NM_003165.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 9.57
• Publications: 1 publications found

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]

STXBP1 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 4

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• genetic developmental and epileptic encephalopathy

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• atypical Rett syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal dominant non-syndromic intellectual disability

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Dravet syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• infantile spasms

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• undetermined early-onset epileptic encephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autism spectrum disorder

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• intellectual disability

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.35074747).
• BP6: Variant 9-127684454-G-A is Benign according to our data. Variant chr9-127684454-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 461291.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003165.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	STXBP1	NM_003165.6	MANE Plus Clinical	c.1789G>A	p.Asp597Asn	missense	Exon 19 of 20	NP_003156.1	P61764-2
	STXBP1	NM_001032221.6	MANE Select	c.1702+1894G>A		intron	N/A	NP_001027392.1	P61764-1
	STXBP1	NM_001374307.2		c.1747G>A	p.Asp583Asn	missense	Exon 20 of 21	NP_001361236.1	A0A1B0GTP9

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	STXBP1	ENST00000373302.8	TSL:1 MANE Plus Clinical	c.1789G>A	p.Asp597Asn	missense	Exon 19 of 20	ENSP00000362399.3	P61764-2
	STXBP1	ENST00000373299.5	TSL:1 MANE Select	c.1702+1894G>A		intron	N/A	ENSP00000362396.2	P61764-1
	STXBP1	ENST00000494254.4	TSL:5	c.1789G>A	p.Asp597Asn	missense	Exon 19 of 19	ENSP00000485397.2	A0A096LP52

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251214 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000290

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461774 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727154

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000224 AC: 1 AN: 44700

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86232

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53394

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111986

Other (OTH) AF: 0.00 AC: 0 AN: 60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	-	Developmental and epileptic encephalopathy (1)
-	-	1	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.34
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.0099	T
Eigen	Uncertain	0.63
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.88	D
M_CAP	Benign	0.030	D
MetaRNN	Benign	0.35	T
MetaSVM	Benign	-0.42	T
PhyloP100		9.6
PrimateAI	Uncertain	0.73	T
PROVEAN	Benign	-0.48	N
REVEL	Benign	0.23
Sift	Benign	0.10	T
Sift4G	Benign	0.54	T
Polyphen		1.0	D
Vest4		0.49
MutPred		0.24		Gain of relative solvent accessibility (P = 0.0479)
MVP		0.50
MPC		1.3
ClinPred		0.95	D
GERP RS		5.3
gMVP		0.82
Mutation Taster		=75/25	polymorphism

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

Other links and lift over

dbSNP: rs749807465; hg19: chr9-130446733;