NM_014363.6:c.5836T>C

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_014363.6(SACS):​c.5836T>C​(p.Trp1946Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,612 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 Pathogenic (★★).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SACS
NM_014363.6 missense

Scores

12
5
2

Clinical Significance

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

Conservation

PhyloP100: 8.95

Publications

5 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 14 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.96
PP5
Variant 13-23338040-A-G is Pathogenic according to our data. Variant chr13-23338040-A-G is described in ClinVar as Pathogenic. ClinVar VariationId is 5517.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.5836T>C p.Trp1946Arg missense_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.5836T>C p.Trp1946Arg missense_variant Exon 10 of 10 5 NM_014363.6 ENSP00000371729.3 Q9NZJ4-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461612
Hom.:
0
Cov.:
36
AF XY:
0.00
AC XY:
0
AN XY:
727114
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33436
American (AMR)
AF:
0.00
AC:
0
AN:
44684
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26122
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53394
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111884
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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

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
Cov.:
33
Alfa
AF:
0.00
Hom.:
0

ClinVar

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

Submissions by phenotype

Charlevoix-Saguenay spastic ataxia Pathogenic:3
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

- -

Jul 01, 2003
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Nov 12, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: SACS c.5836T>C (p.Trp1946Arg) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250862 control chromosomes (gnomAD). c.5836T>C has been reported in the literature as a biallelic genotype in multiple individuals affected with Autosomal Recessive Spastic Ataxia Of Charlevoix-Saguenay (e.g. El Euch-Fayache_2003, Thiffault_2013). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One ClinVar submitter has assessed the variant since 2014: the variant was classified as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Spastic paraplegia Pathogenic:1
Oct 06, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces tryptophan, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 1946 of the SACS protein (p.Trp1946Arg). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with SACS-related conditions (PMID: 12873855, 23250129). It has also been observed to segregate with disease in related individuals. This variant is also known as c.3662T>C, p.Trp1196Arg. ClinVar contains an entry for this variant (Variation ID: 5517). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SACS protein function. For these reasons, this variant has been classified as Pathogenic. -

SACS-related disorder Pathogenic:1
Jan 03, 2024
PreventionGenetics, part of Exact Sciences
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The SACS c.5836T>C variant is predicted to result in the amino acid substitution p.Trp1946Arg. This variant was reported in the homozygous state in 3 affected siblings with Charlevoix-Saguenay spastic ataxia and was heterozygous or not present in 3 unaffected siblings (Reported as 3662T>C in El Euch-Fayache et al 2003. PubMed ID: 12873855). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. This variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
1.0
BayesDel_addAF
Pathogenic
0.58
D
BayesDel_noAF
Pathogenic
0.59
CADD
Pathogenic
26
DANN
Uncertain
0.98
DEOGEN2
Pathogenic
0.80
.;D
Eigen
Uncertain
0.36
Eigen_PC
Uncertain
0.28
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Benign
0.80
T;T
M_CAP
Pathogenic
0.76
D
MetaRNN
Pathogenic
0.96
D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.2
.;M
PhyloP100
8.9
PrimateAI
Uncertain
0.72
T
PROVEAN
Pathogenic
-12
D;D
REVEL
Pathogenic
0.83
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
.;D
Vest4
0.95
MutPred
0.74
.;Gain of catalytic residue at P1947 (P = 0.0112);
MVP
0.94
ClinPred
1.0
D
GERP RS
4.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.2
Varity_R
0.92
gMVP
0.91
Mutation Taster
=4/96
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: rs137853017; hg19: chr13-23912179; API