chr21-32646501-G-A

Variant names:

• chr21-32646501-G-A
• rs147931121
• NM_203446.3:c.3139C>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_203446.3(SYNJ1):​c.3139C>T​(p.Arg1047*) variant causes a stop gained change. The variant allele was found at a frequency of 0.000000684 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SYNJ1 NM_203446.3 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.54
• Publications: 0 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, PanelApp Australia
• early-onset Parkinson disease 20

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp, PanelApp Australia
• 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 10 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

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SYNJ1	NM_203446.3	MANE Select	c.3139C>T	p.Arg1047*	stop_gained	Exon 24 of 33	NP_982271.3	O43426-2
	SYNJ1	NM_003895.4		c.3256C>T	p.Arg1086*	stop_gained	Exon 24 of 32	NP_003886.3
	SYNJ1	NM_001160306.2		c.3124C>T	p.Arg1042*	stop_gained	Exon 23 of 28	NP_001153778.1	A0A0D9SGJ6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SYNJ1	ENST00000674351.1	MANE Select	c.3139C>T	p.Arg1047*	stop_gained	Exon 24 of 33	ENSP00000501530.1	O43426-2
	SYNJ1	ENST00000630077.3	TSL:1	c.3124C>T	p.Arg1042*	stop_gained	Exon 23 of 28	ENSP00000487560.1	A0A0D9SGJ6
	SYNJ1	ENST00000674308.1		c.3139C>T	p.Arg1047*	stop_gained	Exon 24 of 32	ENSP00000501426.1	O43426-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461880 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727238

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112004

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	39
DANN	Uncertain	1.0
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.96	D
PhyloP100		5.5
Vest4		0.67
GERP RS		2.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=8/192	disease causing (fs/PTC)

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: rs147931121; hg19: chr21-34018811; COSMIC: COSV59152851; COSMIC: COSV59152851;