1-202602977-GCCC-GCCCCC

Variant names:

• chr1-202602978-CC-CCC
• NM_177402.5:c.465+19dupG

Variant summary

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

The NM_177402.5(SYT2):​c.465+19dupG variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 0)
• Consequence: SYT2 NM_177402.5 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.81
• Publications: 0 publications found

Genes affected

SYT2 (HGNC:11510): (synaptotagmin 2) This gene encodes a synaptic vesicle membrane protein. The encoded protein is thought to function as a calcium sensor in vesicular trafficking and exocytosis. Mutations in this gene are associated with myasthenic syndrome, presynaptic, congenital, with or without motor neuropathy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2014]

SYT2 Gene-Disease associations (from GenCC):

• congenital myasthenic syndrome 7

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: ClinGen, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia
• myasthenic syndrome, congenital, 7B, presynaptic, autosomal recessive

  Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia
• presynaptic congenital myasthenic syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_177402.5. 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
	SYT2	NM_177402.5	MANE Select	c.465+19dupG		intron	N/A	NP_796376.2
	SYT2	NM_001136504.1		c.465+19dupG		intron	N/A	NP_001129976.1	Q8N9I0

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SYT2	ENST00000367268.5	TSL:1 MANE Select	c.465+19_465+20insG		intron	N/A	ENSP00000356237.4	Q8N9I0
	SYT2	ENST00000930883.1		c.525+19_525+20insG		intron	N/A	ENSP00000600942.1
	SYT2	ENST00000899895.1		c.474+19_474+20insG		intron	N/A	ENSP00000569954.1

Frequencies

GnomAD3 genomes Cov.: 0

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.8
Mutation Taster		=21/79	disease causing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr1-202572106;