9-127690788-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 5P and 3B. PM1 PM2 PP2 BP4 BP6_Moderate

The NM_001032221.6(STXBP1):c.1716C>G(p.Ile572Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 8/13 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: STXBP1 NM_001032221.6 missense
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 1.54

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]

MIR3911 (HGNC:38962): (microRNA 3911) microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts (pri-miRNAs) that can be either protein-coding or non-coding. The primary transcript is cleaved by the Drosha ribonuclease III enzyme to produce an approximately 70-nt stem-loop precursor miRNA (pre-miRNA), which is further cleaved by the cytoplasmic Dicer ribonuclease to generate the mature miRNA and antisense miRNA star (miRNA*) products. The mature miRNA is incorporated into a RNA-induced silencing complex (RISC), which recognizes target mRNAs through imperfect base pairing with the miRNA and most commonly results in translational inhibition or destabilization of the target mRNA. The RefSeq represents the predicted microRNA stem-loop. [provided by RefSeq, Sep 2009]

(HGNC:):

PTRH1 (HGNC:27039): (peptidyl-tRNA hydrolase 1 homolog) Enables RNA binding activity. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_001032221.6
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, STXBP1
• BP4: Computational evidence support a benign effect (MetaRNN=0.3333615).
• BP6: Variant 9-127690788-C-G is Benign according to our data. Variant chr9-127690788-C-G is described in ClinVar as [Likely_benign]. Clinvar id is 1806156.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
STXBP1	NM_001032221.6	c.1716C>G	p.Ile572Met	missense_variant	19/19	ENST00000373299.5
STXBP1	NM_003165.6	c.*30C>G		3_prime_UTR_variant	20/20	ENST00000373302.8
MIR3911	NR_037473.1	n.8G>C		non_coding_transcript_exon_variant	1/1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
STXBP1	ENST00000373299.5	c.1716C>G	p.Ile572Met	missense_variant	19/19	1	NM_001032221.6	A1
STXBP1	ENST00000373302.8	c.*30C>G		3_prime_UTR_variant	20/20	1	NM_003165.6	P3
MIR3911	ENST00000577791.1	n.8G>C		non_coding_transcript_exon_variant	1/1
	ENST00000624141.1	n.53G>C		non_coding_transcript_exon_variant	1/1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 4 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

May 06, 2021

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Likely benign. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with developmental and epileptic encephalopathy 4 (MIM#612164). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from isoleucine to methionine. (I) 0219 - This variant is non-coding in an alternative transcript. This variant is not protein coding in the predominantly used transcript (UCSC, ClinVar). (I) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0503 - Missense variant consistently predicted to be tolerated by multiple in silico tools or not conserved in placental mammals with a minor amino acid change. (SB) 0600 - Variant is located in the annotated Sec1 domain (NCBI, PDB). (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0807 - This variant has no previous evidence of pathogenicity. (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1206 - This variant has been shown to be paternally inherited (LABID). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.23
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	0.0
Cadd	Benign	20
Dann	Benign	0.95
Eigen	Benign	-0.33
Eigen_PC	Benign	-0.27
FATHMM_MKL	Uncertain	0.92	D
M_CAP	Uncertain	0.18	D
MetaRNN	Benign	0.33	T
MutationTaster	Benign	1.0	D;D
ClinPred		0.23	T
GERP RS		0.33

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: chr9-130453067;