rs786204416

Variant summary

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

The NM_014363.6(SACS):c.10466_10467del(p.Ser3489LeufsTer2) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000435 in 1,609,538 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. S3489S) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

SACS
NM_014363.6 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 8.02

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 147 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 13-23333408-AAG-A is Pathogenic according to our data. Variant chr13-23333408-AAG-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188710.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr13-23333408-AAG-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.10466_10467del	p.Ser3489LeufsTer2	frameshift_variant	10/10	ENST00000382292.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SACS	ENST00000382292.9 linkuse as main transcript	c.10466_10467del	p.Ser3489LeufsTer2	frameshift_variant	10/10	5	NM_014363.6	P1	Q9NZJ4-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152156

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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

GnomAD4 exome

AF:

0.00000343

AC:

AN:

1457382

Hom.:

AF XY:

0.00000414

AC XY:

AN XY:

724686

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:

0.00000450

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152156

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74360

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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

Bravo

AF:

0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Charlevoix-Saguenay spastic ataxia

Pathogenic:3

Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Sep 18, 2021	Variant summary: SACS c.10466_10467delCT (p.Ser3489LeufsX2) 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 classified as pathogenic by our laboratory. The variant was absent in 245712 control chromosomes. c.10466_10467delCT has been reported in the literature as a compound heterozygous genotype in at-least one individual affected with Autosomal Recessive Spastic Ataxia Of Charlevoix-Saguenay and has been subsequently cited by others (example Desserre_2011, Criscuolo_2015). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Mar 06, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Aug 16, 2023	- -

Spastic paraplegia

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

May 13, 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.Asn4549Asp) have been determined to be pathogenic (PMID: 15156359, 21507954). 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: 188710). This premature translational stop signal has been observed in individual(s) with SACS-related conditions (PMID: 21597885). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Ser3489Leufs*2) in the SACS gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 1091 amino acid(s) of the SACS protein. -

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