13-23337236-G-T

Variant names:

• chr13-23337236-G-T
• rs138379074
• NM_014363.6:c.6640C>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001437336.1(SACS):​c.6667C>A​(p.Arg2223Ser) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,644 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign 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. R2223L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SACS NM_001437336.1 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.01
• 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: Orphanet, G2P, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Myriad Women’s Health

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.23732045).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001437336.1. 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.6640C>A	p.Arg2214Ser	missense	Exon 10 of 10	NP_055178.3
	SACS	NM_001437336.1		c.6667C>A	p.Arg2223Ser	missense	Exon 11 of 11	NP_001424265.1
	SACS	NM_001278055.2		c.6199C>A	p.Arg2067Ser	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.6640C>A	p.Arg2214Ser	missense	Exon 10 of 10	ENSP00000371729.3
	SACS	ENST00000455470.6	TSL:1	c.2431+4209C>A		intron	N/A	ENSP00000406565.2
	SACS	ENST00000682944.1		c.6667C>A	p.Arg2223Ser	missense	Exon 11 of 11	ENSP00000507173.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461644 Hom.: 0 Cov.: 37 AF XY: 0.00 AC XY: 0 AN XY: 727116

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.00 AC: 0 AN: 86244

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53346

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111902

Other (OTH) AF: 0.00 AC: 0 AN: 60384

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.017	T
BayesDel_noAF	Benign	-0.26
CADD	Benign	21
DANN	Uncertain	0.99
DEOGEN2	Benign	0.15	T
Eigen	Benign	-0.11
Eigen_PC	Benign	0.14
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Benign	0.34	T
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.24	T
MetaSVM	Benign	-0.74	T
MutationAssessor	Benign	0.34	N
PhyloP100		4.0
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	0.28	N
REVEL	Benign	0.25
Sift	Benign	0.063	T
Sift4G	Benign	0.28	T
Polyphen		0.0	B
Vest4		0.092
MutPred		0.53		Gain of catalytic residue at F2215 (P = 0.0074)
MVP		0.80
ClinPred		0.81	D
GERP RS		5.1
Varity_R		0.13
gMVP		0.54
Mutation Taster		=92/8	polymorphism

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: rs138379074; hg19: chr13-23911375;