rs1556857481

Positions:

• chrX-47574544-T-TG

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_006950.3(SYN1):​c.1439_1440insC​(p.Leu481IlefsTer203) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 24)
  • Exomes 𝑓: 0.0 (0 hom. 0 hem.)
  • Failed GnomAD Quality Control
• Consequence: SYN1 NM_006950.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 2.83

Genes affected

SYN1 (HGNC:11494): (synapsin I) This gene is a member of the synapsin gene family. Synapsins encode neuronal phosphoproteins which associate with the cytoplasmic surface of synaptic vesicles. Family members are characterized by common protein domains, and they are implicated in synaptogenesis and the modulation of neurotransmitter release, suggesting a potential role in several neuropsychiatric diseases. This member of the synapsin family plays a role in regulation of axonogenesis and synaptogenesis. The protein encoded serves as a substrate for several different protein kinases and phosphorylation may function in the regulation of this protein in the nerve terminal. Mutations in this gene may be associated with X-linked disorders with primary neuronal degeneration such as Rett syndrome. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 10 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-47574544-T-TG is Pathogenic according to our data. Variant chrX-47574544-T-TG is described in ClinVar as [Likely_pathogenic]. Clinvar id is 496675.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SYN1	NM_006950.3	c.1439_1440insC	p.Leu481IlefsTer203	frameshift_variant	12/13	ENST00000295987.13
SYN1	NM_133499.2	c.1439_1440insC	p.Leu481IlefsTer195	frameshift_variant	12/13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SYN1	ENST00000295987.13	c.1439_1440insC	p.Leu481IlefsTer203	frameshift_variant	12/13	2	NM_006950.3	P3
SYN1	ENST00000340666.5	c.1439_1440insC	p.Leu481IlefsTer195	frameshift_variant	12/13	1		A1
SYN1	ENST00000640721.1	c.70+143_70+144insC		intron_variant		5

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 970603 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 303859

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 24

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Epilepsy, X-linked 1, with variable learning disabilities and behavior disorders Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Institute for Human Genetics, University Hospital Essen	Jul 30, 2022	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Equipe Genetique des Anomalies du Developpement, Université de Bourgogne	Jan 30, 2017	- -

Computational scores

Source: dbNSFP v4.3

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

LitVar

Other links and lift over

dbSNP: rs1556857481; hg19: chrX-47433943;