13-23331188-C-G

Variant names:

• chr13-23331188-C-G
• rs746194271
• NM_014363.6:c.12688G>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_014363.6(SACS):​c.12688G>C​(p.Gly4230Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G4230S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SACS NM_014363.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.90
• Publications: 1 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: Orphanet, G2P, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Myriad Women’s Health

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.911

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SACS	NM_014363.6	MANE Select	c.12688G>C	p.Gly4230Arg	missense	Exon 10 of 10	NP_055178.3
	SACS	NM_001437336.1		c.12715G>C	p.Gly4239Arg	missense	Exon 11 of 11	NP_001424265.1
	SACS	NM_001278055.2		c.12247G>C	p.Gly4083Arg	missense	Exon 8 of 8	NP_001264984.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SACS	ENST00000382292.9	TSL:5 MANE Select	c.12688G>C	p.Gly4230Arg	missense	Exon 10 of 10	ENSP00000371729.3
	SACS	ENST00000455470.6	TSL:1	c.2432-1704G>C		intron	N/A	ENSP00000406565.2
	SACS	ENST00000682944.1		c.12715G>C	p.Gly4239Arg	missense	Exon 11 of 11	ENSP00000507173.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.71	D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.58	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Uncertain	0.79	D
MutationAssessor	Benign	1.1	L
PhyloP100		7.9
PrimateAI	Pathogenic	0.92	D
PROVEAN	Uncertain	-3.8	D
REVEL	Pathogenic	0.89
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.88
MutPred		0.61		Gain of sheet (P = 0.0101)
MVP		0.91
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.75
gMVP		0.86
Mutation Taster		=10/90	disease causing

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: rs746194271; hg19: chr13-23905327;