13-23341274-T-C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBS1_Supporting

The NM_014363.6(SACS):c.2602A>G(p.Ile868Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000762 in 1,613,676 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000044 ( 0 hom. )

Consequence

SACS
NM_014363.6 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:1

Conservation

PhyloP100: 1.16

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

SACS links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.016664624).

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000387 (59/152372) while in subpopulation AFR AF = 0.0013 (54/41592). AF 95% confidence interval is 0.00102. There are 0 homozygotes in GnomAd4. There are 24 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SACS	NM_014363.6 link	c.2602A>G	p.Ile868Val	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
SACS	ENST00000382292.9 link	c.2602A>G	p.Ile868Val	missense_variant	Exon 10 of 10	5	NM_014363.6	ENSP00000371729.3		Q9NZJ4-1

Frequencies

GnomAD3 genomes

AF:

0.000381

AC:

AN:

152254

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00128

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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:

0.000478

GnomAD2 exomes

AF:

0.0000918

AC:

AN:

250498

AF XY:

0.0000295

show subpopulations

Gnomad AFR exome

AF:

0.00132

Gnomad AMR exome

AF:

0.0000580

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000438

AC:

AN:

1461304

Hom.:

Cov.:

AF XY:

0.0000358

AC XY:

AN XY:

726936

show subpopulations

African (AFR)

AF:

0.00146

AC:

AN:

33454

American (AMR)

AF:

0.0000671

AC:

AN:

44686

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26126

East Asian (EAS)

AF:

0.00

AC:

AN:

39678

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86146

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53402

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111662

Other (OTH)

AF:

0.000149

AC:

AN:

60382

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.505

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.000387

AC:

AN:

152372

Hom.:

Cov.:

AF XY:

0.000322

AC XY:

AN XY:

74516

show subpopulations

African (AFR)

AF:

0.00130

AC:

AN:

41592

American (AMR)

AF:

0.000196

AC:

AN:

15306

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68030

Other (OTH)

AF:

0.000473

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.498

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.000174

Hom.:

Bravo

AF:

0.000382

ESP6500AA

AF:

0.00136

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000132

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Jun 28, 2019

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Jul 23, 2018

Athena Diagnostics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Charlevoix-Saguenay spastic ataxia

Uncertain:2

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. -

Inborn genetic diseases

Uncertain:1

Feb 09, 2022

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.2602A>G (p.I868V) alteration is located in exon 10 (coding exon 9) of the SACS gene. This alteration results from a A to G substitution at nucleotide position 2602, causing the isoleucine (I) at amino acid position 868 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hereditary spastic paraplegia

Uncertain:1

Dec 12, 2016

Genome Diagnostics Laboratory, The Hospital for Sick Children

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Spastic paraplegia

Benign:1

Aug 29, 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

0.076

BayesDel_addAF

Benign

-0.45

BayesDel_noAF

Benign

-0.46

CADD

Benign

(source)

DANN

Benign

0.58

DEOGEN2

Benign

0.19

.;T

Eigen

Benign

-0.71

Eigen_PC

Benign

-0.60

FATHMM_MKL

Benign

0.61

LIST_S2

Benign

0.71

T;T

M_CAP

Benign

0.028

MetaRNN

Benign

0.017

T;T

MetaSVM

Benign

-0.89

MutationAssessor

Benign

-0.065

.;N

PhyloP100

1.2

PrimateAI

Benign

0.39

PROVEAN

Benign

-0.39

N;N

REVEL

Benign

0.13

Sift

Benign

0.14

T;T

Sift4G

Benign

0.62

T;T

Polyphen

0.0

.;B

Vest4

0.065

MVP

0.60

ClinPred

0.0050

GERP RS

-0.45

Varity_R

0.018

gMVP

0.23

Mutation Taster

=74/26

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over