rs772742353

Positions:

• chr13-23335462-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_014363.6(SACS):​c.8414C>T​(p.Thr2805Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,461,412 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000011 (0 hom.)
• Consequence: SACS NM_014363.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: 9.60

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.749

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SACS	NM_014363.6	c.8414C>T	p.Thr2805Ile	missense_variant	10/10	ENST00000382292.9	NP_055178.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SACS	ENST00000382292.9	c.8414C>T	p.Thr2805Ile	missense_variant	10/10	5	NM_014363.6	ENSP00000371729.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000120 AC: 3 AN: 250244 Hom.: 0 AF XY: 0.0000222 AC XY: 3 AN XY: 135272

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000177

Gnomad OTH exome AF: 0.000164

GnomAD4 exome AF: 0.0000109 AC: 16 AN: 1461412 Hom.: 0 Cov.: 37 AF XY: 0.0000151 AC XY: 11 AN XY: 727016

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000135

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000624 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Athena Diagnostics	May 23, 2023	Available data are insufficient to determine the clinical significance of the variant at this time. The frequency of this variant in the general population is uninformative in assessment of its pathogenicity (http://gnomad.broadinstitute.org). Computational tools disagree on the variant's effect on normal protein function. -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Dec 31, 2014	- -
Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2018	- -

Charlevoix-Saguenay spastic ataxia Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -

Spastic paraplegia Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 27, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.060
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.26	.;T
Eigen	Uncertain	0.50
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Benign	0.058	D
MetaRNN	Pathogenic	0.75	D;D
MetaSVM	Uncertain	0.15	D
MutationAssessor	Uncertain	2.7	.;M
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-1.2	N;N
REVEL	Uncertain	0.47
Sift	Benign	0.035	D;D
Sift4G	Uncertain	0.0090	D;D
Polyphen		0.93	.;P
Vest4		0.74
MutPred		0.43		.;Gain of catalytic residue at D2807 (P = 0.0014);
MVP		0.92
ClinPred		0.73	D
GERP RS		5.7
Varity_R		0.13
gMVP		0.51

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

Other links and lift over

dbSNP: rs772742353; hg19: chr13-23909601;