NM_203446.3:c.395G>A

Variant names:

• chr21-32699922-C-T
• rs1555907463
• NM_203446.3:c.395G>A

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_203446.3(SYNJ1):​c.395G>A​(p.Trp132*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SYNJ1 NM_203446.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.46
• Publications: 2 publications found

Genes affected

SYNJ1 (HGNC:11503): (synaptojanin 1) This gene encodes a phosphoinositide phosphatase that regulates levels of membrane phosphatidylinositol-4,5-bisphosphate. As such, expression of this enzyme may affect synaptic transmission and membrane trafficking. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2011]

SYNJ1 Gene-Disease associations (from GenCC):

• genetic developmental and epileptic encephalopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• developmental and epileptic encephalopathy, 53

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• early-onset Parkinson disease 20

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• undetermined early-onset epileptic encephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• atypical juvenile parkinsonism

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• young-onset Parkinson disease

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 21-32699922-C-T is Pathogenic according to our data. Variant chr21-32699922-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 549503.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_203446.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SYNJ1	NM_203446.3	MANE Select	c.395G>A	p.Trp132*	stop_gained	Exon 4 of 33	NP_982271.3
	SYNJ1	NM_003895.4		c.512G>A	p.Trp171*	stop_gained	Exon 4 of 32	NP_003886.3
	SYNJ1	NM_001160306.2		c.395G>A	p.Trp132*	stop_gained	Exon 4 of 28	NP_001153778.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SYNJ1	ENST00000674351.1	MANE Select	c.395G>A	p.Trp132*	stop_gained	Exon 4 of 33	ENSP00000501530.1
	SYNJ1	ENST00000433931.7	TSL:1	c.512G>A	p.Trp171*	stop_gained	Exon 4 of 32	ENSP00000409667.2
	SYNJ1	ENST00000630077.3	TSL:1	c.395G>A	p.Trp132*	stop_gained	Exon 4 of 28	ENSP00000487560.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Early-onset Parkinson disease 20 Pathogenic:1

Aug 30, 2016

Institute for Human Genetics, University Medical Center Freiburg

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: case-control

This variant was found in two German patients with epilepsy early in the disease course, followed by progressive generalized dopa-responsive dystonia associated with severe action tremor of the tongue, head, and extremities in their early teen years, and cognitive deterioration. We identified compound heterozygous mutations (NP_982271.2:p.Trp171*/NP_982271.2:p.Arg258Gln) in the SYNJ1 gene, affecting the N-terminal suppressor of actin1 (SAC1)-like domain of the SYNJ1 protein.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	37
DANN	Uncertain	0.99
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		7.5
Vest4		0.82
GERP RS		5.6
Mutation Taster		=0/200	disease causing (ClinVar)

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: rs1555907463; hg19: chr21-34072232;