Genetic Variant NM_014363.6:c.972C>A (chr13-23355640-G-T) – ACMG Classification: Benign (-13 pts)

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_014363.6(SACS):c.972C>A(p.Asp324Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000164 in 1,614,024 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. D324D) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00017 ( 2 hom. )

Consequence

SACS
NM_014363.6 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:3

Conservation

PhyloP100: 0.155

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

SACS links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -13 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.013695121).

BP6

Variant 13-23355640-G-T is Benign according to our data. Variant chr13-23355640-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 528018.

BS1

Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.0000592 (9/152134) while in subpopulation SAS AF = 0.00187 (9/4820). AF 95% confidence interval is 0.000974. There are 0 homozygotes in GnomAd4. There are 7 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.

BS2

High Homozygotes in GnomAdExome4 at 2 AR gene

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_014363.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
SACS	NM_014363.6	MANE Select	c.972C>A	p.Asp324Glu	missense	Exon 8 of 10	NP_055178.3
SACS	NM_001437336.1		c.972C>A	p.Asp324Glu	missense	Exon 8 of 11	NP_001424265.1
SACS	NM_001278055.2		c.531C>A	p.Asp177Glu	missense	Exon 6 of 8	NP_001264984.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
SACS	ENST00000382292.9	TSL:5 MANE Select	c.972C>A	p.Asp324Glu	missense	Exon 8 of 10	ENSP00000371729.3
SACS	ENST00000455470.6	TSL:1	c.972C>A	p.Asp324Glu	missense	Exon 8 of 11	ENSP00000406565.2
SACS	ENST00000682944.1		c.972C>A	p.Asp324Glu	missense	Exon 8 of 11	ENSP00000507173.1

Frequencies

GnomAD3 genomes

AF:

0.0000592

AC:

AN:

152016

Hom.:

Cov.:

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:

0.00187

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000354

AC:

AN:

251426

AF XY:

0.000368

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:

0.00000879

Gnomad OTH exome

AF:

0.000489

GnomAD4 exome

AF:

0.000174

AC:

255

AN:

1461890

Hom.:

Cov.:

AF XY:

0.000220

AC XY:

160

AN XY:

727244

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00272

AC:

235

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1112012

Other (OTH)

AF:

0.000331

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.484

Heterozygous variant carriers

105

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

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:

0.0000592

AC:

AN:

152134

Hom.:

Cov.:

AF XY:

0.0000942

AC XY:

AN XY:

74348

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41492

American (AMR)

AF:

0.00

AC:

AN:

15262

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5184

South Asian (SAS)

AF:

0.00187

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10570

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68024

Other (OTH)

AF:

0.00

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

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:

0.0000434

Hom.:

Bravo

AF:

0.0000302

ExAC

AF:

0.000379

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Charlevoix-Saguenay spastic ataxia

Uncertain:1Benign:1

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.

Sep 05, 2021

Genome-Nilou Lab

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Uncertain:1

Feb 25, 2016

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

Spastic paraplegia

Benign:1

Sep 06, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

SACS-related disorder

Benign:1

May 10, 2022

PreventionGenetics, part of Exact Sciences

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications).

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.12

CADD

Benign

3.7

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.18

Eigen

Benign

-0.88

Eigen_PC

Benign

-1.0

FATHMM_MKL

Uncertain

0.88

LIST_S2

Benign

0.75

M_CAP

Uncertain

0.16

MetaRNN

Benign

0.014

MetaSVM

Uncertain

0.53

MutationAssessor

Uncertain

2.6

PhyloP100

0.15

PrimateAI

Benign

0.45

PROVEAN

Benign

-0.65

REVEL

Uncertain

0.45

Sift

Benign

0.20

Sift4G

Uncertain

0.011

Polyphen

0.43

Vest4

0.41

MutPred

0.39

Loss of sheet (P = 0.0817)

MVP

0.65

ClinPred

0.12

GERP RS

-4.8

Varity_R

0.14

gMVP

0.44

Mutation Taster

=287/13

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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over