chr13-23334311-TAAAC-T

Variant names:

• chr13-23334311-TAAAC-T
• rs1060503431
• NM_014363.6:c.9561_9564delGTTT

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_014363.6(SACS):​c.9561_9564delGTTT​(p.Phe3188fs) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,456,752 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SACS NM_014363.6 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 8.87
• Publications: 0 publications found

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: Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, PanelApp Australia, G2P, Myriad Women’s Health, Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 267 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 13-23334311-TAAAC-T is Pathogenic according to our data. Variant chr13-23334311-TAAAC-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 411690.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SACS	NM_014363.6	MANE Select	c.9561_9564delGTTT	p.Phe3188fs	frameshift	Exon 10 of 10	NP_055178.3
	SACS	NM_001437336.1		c.9588_9591delGTTT	p.Phe3197fs	frameshift	Exon 11 of 11	NP_001424265.1	A0A804HIQ1
	SACS	NM_001278055.2		c.9120_9123delGTTT	p.Phe3041fs	frameshift	Exon 8 of 8	NP_001264984.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SACS	ENST00000382292.9	TSL:5 MANE Select	c.9561_9564delGTTT	p.Phe3188fs	frameshift	Exon 10 of 10	ENSP00000371729.3	Q9NZJ4-1
	SACS	ENST00000455470.6	TSL:1	c.2432-4831_2432-4828delGTTT		intron	N/A	ENSP00000406565.2	H0Y6M8
	SACS	ENST00000682944.1		c.9588_9591delGTTT	p.Phe3197fs	frameshift	Exon 11 of 11	ENSP00000507173.1	A0A804HIQ1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1456752 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 724382

African (AFR) AF: 0.00 AC: 0 AN: 33140

American (AMR) AF: 0.00 AC: 0 AN: 44430

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26062

East Asian (EAS) AF: 0.0000254 AC: 1 AN: 39436

South Asian (SAS) AF: 0.00 AC: 0 AN: 85522

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53168

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5710

European-Non Finnish (NFE) AF: 9.02e-7 AC: 1 AN: 1109162

Other (OTH) AF: 0.00 AC: 0 AN: 60122

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
4	-	-	Charlevoix-Saguenay spastic ataxia (4)
1	-	-	Spastic paraplegia (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		8.9
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs1060503431; hg19: chr13-23908450;