rs281865120

Variant summary

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

The NM_014363.6(SACS):c.12160C>T(p.Gln4054Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,613,820 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Q4054Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

SACS
NM_014363.6 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:11O:1

Conservation

PhyloP100: 9.92

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 66 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 13-23331716-G-A is Pathogenic according to our data. Variant chr13-23331716-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 38458.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr13-23331716-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SACS	NM_014363.6 linkuse as main transcript	c.12160C>T	p.Gln4054Ter	stop_gained	10/10	ENST00000382292.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SACS	ENST00000382292.9 linkuse as main transcript	c.12160C>T	p.Gln4054Ter	stop_gained	10/10	5	NM_014363.6	P1	Q9NZJ4-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152162

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000160

AC:

AN:

250398

Hom.:

AF XY:

0.00000739

AC XY:

AN XY:

135352

show subpopulations

Gnomad AFR exome

AF:

0.00

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:

0.0000354

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000109

AC:

AN:

1461658

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727124

show subpopulations

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:

0.0000135

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152162

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74338

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000384

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:11Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Charlevoix-Saguenay spastic ataxia

Pathogenic:5Other:1

Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Oct 13, 2021	- -
not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	May 31, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 18, 2022	Variant summary: SACS c.12160C>T (p.Gln4054X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been reported in HGMD in association with Spastic ataxia, Charlevoix-Saguenay. The variant allele was found at a frequency of 1.6e-05 in 250398 control chromosomes. c.12160C>T has been reported in the literature in multiple individuals affected with Autosomal Recessive Spastic Ataxia Of Charlevoix-Saguenay (eg. Vermeer_2008, Vermeer_2009). These data indicate that the variant is very likely to be associated with disease. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Apr 05, 2016	- -

not provided

Pathogenic:5

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Nov 06, 2022	Nonsense variant predicted to result in protein truncation, as the last 526 amino acids are lost, 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: 23280630, 27288452, 18465152, 31589614) -
Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2016	- -
Pathogenic, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, Amsterdam University Medical Center	-	- -

Spastic paraplegia

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jun 03, 2023

For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the SACS protein in which other variant(s) (p.Arg4325*, p.Glu4309*, p.Phe4352Leufs*11) have been determined to be pathogenic (PMID: 16944349, 23497566, 26288984). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. ClinVar contains an entry for this variant (Variation ID: 38458). This premature translational stop signal has been observed in individuals with hereditary spastic paraplegia (PMID: 18465152, 27288452). This variant is present in population databases (rs281865120, gnomAD 0.004%). This sequence change creates a premature translational stop signal (p.Gln4054*) in the SACS gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 526 amino acid(s) of the SACS protein. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.55

BayesDel_noAF

Pathogenic

0.58

Cadd

Pathogenic

Dann

Uncertain

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Uncertain

0.97

MutationTaster

Benign

1.0

D;D;D

Vest4

0.98

GERP RS

5.3

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

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