rs750181262

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2PM5PP3_ModeratePP5

The NM_014363.6(SACS):c.8108G>A(p.Arg2703His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000929 in 1,613,856 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/20 in silico tools predict a damaging outcome for this variant. 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. R2703C) has been classified as Likely pathogenic.

Frequency

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

Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

SACS
NM_014363.6 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:4

Conservation

PhyloP100: 7.57

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr13-23335769-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1458362.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.903

PP5

Variant 13-23335768-C-T is Pathogenic according to our data. Variant chr13-23335768-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 553081.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Pathogenic=1, Uncertain_significance=3}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SACS	NM_014363.6 linkuse as main transcript	c.8108G>A	p.Arg2703His	missense_variant	10/10	ENST00000382292.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SACS	ENST00000382292.9 linkuse as main transcript	c.8108G>A	p.Arg2703His	missense_variant	10/10	5	NM_014363.6	P1	Q9NZJ4-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152096

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:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000120

AC:

AN:

250978

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135644

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.0000993

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000958

AC:

AN:

1461760

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727182

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000117

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152096

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74318

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Charlevoix-Saguenay spastic ataxia

Pathogenic:1Uncertain:3

Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Aug 14, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Aug 02, 2017	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 24, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -

Spastic paraplegia

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 27, 2023

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 2703 of the SACS protein (p.Arg2703His). This variant is present in population databases (rs750181262, gnomAD 0.01%). This missense change has been observed in individuals with clinical features of hereditary spastic paraplegia (PMID: 26288984; Invitae). ClinVar contains an entry for this variant (Variation ID: 553081). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SACS protein function. This variant disrupts the p.Arg2703 amino acid residue in SACS. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 16007637, 29277257). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 17, 2022

Not observed at a significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 29482223, 26288984) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.98

BayesDel_addAF

Pathogenic

0.53

BayesDel_noAF

Pathogenic

0.54

Cadd

Pathogenic

Dann

Pathogenic

1.0

Eigen

Pathogenic

0.84

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Uncertain

0.94

LIST_S2

Uncertain

0.97

D;D

M_CAP

Pathogenic

0.44

MetaRNN

Pathogenic

0.90

D;D

MetaSVM

Pathogenic

1.0

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.64

PROVEAN

Pathogenic

-4.5

D;D

REVEL

Pathogenic

0.93

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

1.0

.;D

Vest4

0.95

MutPred

0.66

.;Gain of catalytic residue at L2702 (P = 2e-04);

MVP

0.95

ClinPred

1.0

GERP RS

5.6

Varity_R

0.81

gMVP

0.90

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over