rs147949881

Variant summary

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

The NM_014363.6(SACS):​c.6952G>A​(p.Ala2318Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000331 in 1,613,750 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A2318V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00024 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00034 ( 0 hom. )

Consequence

SACS
NM_014363.6 missense

Scores

4
10
5

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:9B:2

Conservation

PhyloP100: 5.70

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: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SACSNM_014363.6 linkc.6952G>A p.Ala2318Thr 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.6952G>A p.Ala2318Thr missense_variant Exon 10 of 10 5 NM_014363.6 ENSP00000371729.3 Q9NZJ4-1

Frequencies

GnomAD3 genomes
AF:
0.000237
AC:
36
AN:
152124
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000622
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000426
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000199
AC:
50
AN:
250954
AF XY:
0.000170
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000868
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000326
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000341
AC:
498
AN:
1461626
Hom.:
0
Cov.:
37
AF XY:
0.000352
AC XY:
256
AN XY:
727098
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33474
American (AMR)
AF:
0.0000671
AC:
3
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39682
South Asian (SAS)
AF:
0.000429
AC:
37
AN:
86244
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000383
AC:
426
AN:
1111804
Other (OTH)
AF:
0.000480
AC:
29
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
29
58
87
116
145
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
20
40
60
80
100
<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:
0.000237
AC:
36
AN:
152124
Hom.:
0
Cov.:
33
AF XY:
0.000175
AC XY:
13
AN XY:
74310
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41444
American (AMR)
AF:
0.0000655
AC:
1
AN:
15260
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.000622
AC:
3
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000426
AC:
29
AN:
68006
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
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

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:
0.000347
Hom.:
0
Bravo
AF:
0.000227
TwinsUK
AF:
0.000539
AC:
2
ALSPAC
AF:
0.00
AC:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.00105
AC:
9
ExAC
AF:
0.000198
AC:
24
EpiCase
AF:
0.000600
EpiControl
AF:
0.000356

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:9Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Charlevoix-Saguenay spastic ataxia Uncertain:4
-
Neuberg Centre For Genomic Medicine, NCGM
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The missense variant p.A2318T in SACS (NM_014363.6) has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. It has been submitted to ClinVar with varying interpretations of pathogenicity- Uncertain Significance/ Likely Benign., however no details are available for independent assessment. The p.A2318T missense variant is predicted to be damaging by both SIFT and PolyPhen2. The alanine residue at codon 2318 of SACS is conserved in all mammalian species. The nucleotide c.6952 in SACS is predicted conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Uncertain Significance. -

Sep 05, 2021
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Dec 24, 2019
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not provided Uncertain:2Benign:1
Aug 23, 2022
Athena Diagnostics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 20, 2023
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 18, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Identified in a patient with spinocerebellar ataxia in published literature, although clinical details and segregation data was not provided (PMID: 34445196); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 34445196) -

Inborn genetic diseases Uncertain:1
Jun 29, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.6952G>A (p.A2318T) alteration is located in exon 10 (coding exon 9) of the SACS gene. This alteration results from a G to A substitution at nucleotide position 6952, causing the alanine (A) at amino acid position 2318 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hereditary spastic paraplegia Uncertain:1
Oct 01, 2019
Genome Diagnostics Laboratory, The Hospital for Sick Children
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Spastic ataxia Uncertain:1
Jan 04, 2021
Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Fondazione Stella Maris
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

- -

Spastic paraplegia Benign:1
Aug 27, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.19
BayesDel_addAF
Uncertain
0.044
T
BayesDel_noAF
Pathogenic
0.14
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.17
.;T
Eigen
Uncertain
0.37
Eigen_PC
Uncertain
0.38
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Pathogenic
0.97
D;D
M_CAP
Uncertain
0.24
D
MetaRNN
Uncertain
0.55
D;D
MetaSVM
Uncertain
0.54
D
MutationAssessor
Uncertain
2.1
.;M
PhyloP100
5.7
PrimateAI
Uncertain
0.66
T
PROVEAN
Benign
-0.48
N;N
REVEL
Pathogenic
0.68
Sift
Benign
0.26
T;T
Sift4G
Pathogenic
0.0
D;D
Polyphen
0.98
.;D
Vest4
0.71
MVP
0.91
ClinPred
0.16
T
GERP RS
5.1
Varity_R
0.075
gMVP
0.41
Mutation Taster
=80/20
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: rs147949881; hg19: chr13-23911063; COSMIC: COSV104428938; API