20-10275516-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_130811.4(SNAP25):​c.25A>C​(p.Asn9His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N9S) has been classified as Benign.

Frequency

Genomes: not found (cov: 33)

Consequence

SNAP25
NM_130811.4 missense

Scores

4
6
9

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.58
Variant links:
Genes affected
SNAP25 (HGNC:11132): (synaptosome associated protein 25) Synaptic vesicle membrane docking and fusion is mediated by SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) located on the vesicle membrane (v-SNAREs) and the target membrane (t-SNAREs). The assembled v-SNARE/t-SNARE complex consists of a bundle of four helices, one of which is supplied by v-SNARE and the other three by t-SNARE. For t-SNAREs on the plasma membrane, the protein syntaxin supplies one helix and the protein encoded by this gene contributes the other two. Therefore, this gene product is a presynaptic plasma membrane protein involved in the regulation of neurotransmitter release. Two alternative transcript variants encoding different protein isoforms have been described for this gene. [provided by RefSeq, Jul 2008]
SNAP25-AS1 (HGNC:44312): (SNAP25 antisense RNA 1)

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM1
In a helix (size 72) in uniprot entity SNP25_HUMAN there are 11 pathogenic changes around while only 3 benign (79%) in NM_130811.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SNAP25. . Gene score misZ 2.9553 (greater than the threshold 3.09). Trascript score misZ 3.1929 (greater than threshold 3.09). GenCC has associacion of gene with presynaptic congenital myasthenic syndrome, congenital myasthenic syndrome 18, developmental and epileptic encephalopathy.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
SNAP25NM_130811.4 linkuse as main transcriptc.25A>C p.Asn9His missense_variant 2/8 ENST00000254976.7

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
SNAP25ENST00000254976.7 linkuse as main transcriptc.25A>C p.Asn9His missense_variant 2/81 NM_130811.4 P5P60880-1
SNAP25-AS1ENST00000421143.6 linkuse as main transcriptn.6-78579T>G intron_variant, non_coding_transcript_variant 5

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
Cov.:
30
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Congenital myasthenic syndrome 18 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 15, 2022In 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with SNAP25-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces asparagine, which is neutral and polar, with histidine, which is basic and polar, at codon 9 of the SNAP25 protein (p.Asn9His). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Uncertain
0.025
T
BayesDel_noAF
Benign
-0.20
CADD
Uncertain
24
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.45
T;.;.
Eigen
Uncertain
0.60
Eigen_PC
Pathogenic
0.68
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.97
D;D;D
M_CAP
Benign
0.0068
T
MetaRNN
Uncertain
0.43
T;T;T
MetaSVM
Benign
-0.67
T
MutationAssessor
Benign
1.7
L;L;.
MutationTaster
Benign
1.0
D;D
PrimateAI
Pathogenic
0.86
D
PROVEAN
Benign
-1.8
N;N;N
REVEL
Benign
0.29
Sift
Benign
0.039
D;D;T
Sift4G
Uncertain
0.054
T;T;T
Polyphen
0.95
P;D;.
Vest4
0.78
MutPred
0.19
Gain of catalytic residue at L11 (P = 0.112);Gain of catalytic residue at L11 (P = 0.112);Gain of catalytic residue at L11 (P = 0.112);
MVP
0.34
MPC
0.39
ClinPred
0.87
D
GERP RS
6.1
Varity_R
0.65
gMVP
0.80

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr20-10256164; API