rs1269342975

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 4P and 4B. PM1PM2BP4_Strong

The NM_014363.6(SACS):​c.7981A>G​(p.Ile2661Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,186 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

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

Consequence

SACS
NM_014363.6 missense

Scores

19

Clinical Significance

Uncertain significance criteria provided, single submitter U:2

Conservation

PhyloP100: 0.837

Publications

0 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: Uncertain_significance. The variant received 0 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 6 uncertain in NM_014363.6
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.06647056).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SACSNM_014363.6 linkc.7981A>G p.Ile2661Val 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.7981A>G p.Ile2661Val missense_variant Exon 10 of 10 5 NM_014363.6 ENSP00000371729.3 Q9NZJ4-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152186
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
Cov.:
37
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152186
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74342
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Spastic paraplegia Uncertain:1
Feb 12, 2020
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine with valine at codon 2661 of the SACS protein (p.Ile2661Val). The isoleucine residue is weakly conserved and there is a small physicochemical difference between isoleucine and valine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with SACS-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Charlevoix-Saguenay spastic ataxia Uncertain:1
Jun 09, 2021
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.053
BayesDel_addAF
Benign
-0.19
T
BayesDel_noAF
Benign
-0.51
CADD
Benign
6.4
DANN
Benign
0.27
DEOGEN2
Benign
0.12
.;T
Eigen
Benign
-0.97
Eigen_PC
Benign
-0.87
FATHMM_MKL
Benign
0.073
N
LIST_S2
Benign
0.79
T;T
M_CAP
Benign
0.046
D
MetaRNN
Benign
0.066
T;T
MetaSVM
Benign
-0.83
T
MutationAssessor
Benign
-2.4
.;N
PhyloP100
0.84
PrimateAI
Benign
0.28
T
PROVEAN
Benign
0.55
N;N
REVEL
Benign
0.13
Sift
Benign
0.39
T;T
Sift4G
Benign
1.0
T;T
Polyphen
0.0
.;B
Vest4
0.025
MutPred
0.33
.;Gain of catalytic residue at A2658 (P = 0.0045);
MVP
0.42
ClinPred
0.16
T
GERP RS
1.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.023
gMVP
0.097
Mutation Taster
=93/7
polymorphism

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: rs1269342975; hg19: chr13-23910034; API