13-23335082-GTTTT-GTTTTT

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_014363.6(SACS):c.8793dupA(p.Arg2932ThrfsTer7) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,613,308 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

SACS
NM_014363.6 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: -0.798

Variant links:

Genes affected

SACS (HGNC:10519): (sacsin molecular chaperone) This gene encodes the sacsin protein, which includes a UbL domain at the N-terminus, a DnaJ domain, and a HEPN domain at the C-terminus. The gene is highly expressed in the central nervous system, also found in skin, skeletal muscles and at low levels in the pancreas. This gene includes a very large exon spanning more than 12.8 kb. Mutations in this gene result in autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), a neurodegenerative disorder characterized by early-onset cerebellar ataxia with spasticity and peripheral neuropathy. The authors of a publication on the effects of siRNA-mediated sacsin knockdown concluded that sacsin protects against mutant ataxin-1 and suggest that "the large multi-domain sacsin protein is able to recruit Hsp70 chaperone action and has the potential to regulate the effects of other ataxia proteins" (Parfitt et al., PubMed: 19208651). A pseudogene associated with this gene is located on chromosome 11. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2013]

SACS links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 55 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 13-23335082-G-GT is Pathogenic according to our data. Variant chr13-23335082-G-GT is described in ClinVar as [Likely_pathogenic]. Clinvar id is 959991.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SACS	NM_014363.6 link	c.8793dupA	p.Arg2932ThrfsTer7	frameshift_variant	Exon 10 of 10	ENST00000382292.9	NP_055178.3	Q9NZJ4-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SACS	ENST00000382292.9 link	c.8793dupA	p.Arg2932ThrfsTer7	frameshift_variant	Exon 10 of 10	5	NM_014363.6	ENSP00000371729.3		Q9NZJ4-1

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152022

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000798

AC:

AN:

250652

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135498

show subpopulations

Gnomad AFR exome

AF:

0.0000616

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000882

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000684

AC:

AN:

1461286

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

726894

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

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:

0.00000810

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152022

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74272

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000453

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:3

Jun 10, 2020

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant results in a shift of the reading frame, and is therefore predicted to result in the loss of a functional protein. Found in at least one patient with expected phenotype for this gene, and found in general population data at a frequency that is consistent with pathogenicity. -

Sep 08, 2020

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

DNA sequence analysis of the SACS gene demonstrated a one base pair duplication in exon 10, c.8793dup. This sequence change results in an amino acid frameshift and creates a premature stop codon 7 amino acids downstream of the variant, p.Arg2932Thrfs*7. This sequence change is not predicted to result in nonsense mediated decay, but does disrupt the c-terminal domain of the SACS protein. This sequencing change has been described in the gnomAD database with a low overall population frequency of 0.001% and a frequency of 0.004% in the African sub group (dbSNP rs767871841). Other truncating variants within this region and downstream of this variant have been reported in patients with SACS-related disorders (PMIDs: 18465152, 15156359, 22816526). Collectively these evidences indicate that, this p.Arg2932Thrfs*7 sequence change is pathogenic. -

Apr 29, 2024

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Frameshift variant predicted to result in protein truncation, as the last 1648 amino acids are replaced with 6 different amino acids, and other loss-of-function variants have been reported downstream in HGMD; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 11788093, 34663476, 10655055, 19892370, 22307627, 21745802) -

Charlevoix-Saguenay spastic ataxia

Pathogenic:3

Sep 05, 2021

Genome-Nilou Lab

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 20, 2024

Centre for Inherited Metabolic Diseases, Karolinska University Hospital

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 19, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Spastic paraplegia

Pathogenic:1

Oct 08, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg2932Thrfs*7) in the SACS gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 1648 amino acid(s) of the SACS protein. This variant is present in population databases (rs767871841, gnomAD 0.004%). This variant has not been reported in the literature in individuals affected with SACS-related conditions. ClinVar contains an entry for this variant (Variation ID: 959991). This variant disrupts a region of the SACS protein in which other variant(s) (p.Ile2949Phefs*4, p.Arg3903*) have been determined to be pathogenic (PMID: 10655055, 11788093, 19892370, 21745802, 22307627). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Hereditary spastic paraplegia

Pathogenic:1

Feb 01, 2019

Genome Diagnostics Laboratory, The Hospital for Sick Children

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over