rs773182375

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_014363.6(SACS):​c.7205_7206delTT​(p.Leu2402ArgfsTer6) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,613,698 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

SACS
NM_014363.6 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 1.42

Publications

2 publications found
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 Gene-Disease associations (from GenCC):
  • Charlevoix-Saguenay spastic ataxia
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Myriad Women’s Health

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 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 432 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 13-23336669-CAA-C is Pathogenic according to our data. Variant chr13-23336669-CAA-C is described in ClinVar as Pathogenic. ClinVar VariationId is 458274.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
SACSNM_014363.6 linkc.7205_7206delTT p.Leu2402ArgfsTer6 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
SACSENST00000382292.9 linkc.7205_7206delTT p.Leu2402ArgfsTer6 frameshift_variant Exon 10 of 10 5 NM_014363.6 ENSP00000371729.3 Q9NZJ4-1

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152066
Hom.:
0
Cov.:
33
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
250642
AF XY:
0.0000369
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000353
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000192
AC:
28
AN:
1461632
Hom.:
0
AF XY:
0.0000234
AC XY:
17
AN XY:
727102
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33470
American (AMR)
AF:
0.00
AC:
0
AN:
44690
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39688
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86238
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53392
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000225
AC:
25
AN:
1111880
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60378
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.461
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000132
AC:
2
AN:
152066
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74284
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41394
American (AMR)
AF:
0.00
AC:
0
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
67998
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000189

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Charlevoix-Saguenay spastic ataxia Pathogenic:4
Jan 01, 2022
PROSPAX: an integrated multimodal progression chart in spastic ataxias, Center for Neurology; Hertie-Institute for Clinical Brain Research
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

Aug 19, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Sep 09, 2023
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 28, 2022
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Spastic paraplegia Pathogenic:1
Feb 17, 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.Leu2402Argfs*6) in the SACS gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 2178 amino acid(s) of the SACS protein. This variant is present in population databases (rs773182375, 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: 458274). This variant disrupts a region of the SACS protein in which other variant(s) (p.Arg3903*) have been determined to be pathogenic (PMID: 19892370, 21745802). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
1.4
Mutation Taster
=0/200
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs773182375; hg19: chr13-23910808; API