chr13-23330302-G-A

Variant names:

• chr13-23330302-G-A
• rs750412600
• NM_014363.6:c.13574C>T

Variant summary

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

The NM_014363.6(SACS):​c.13574C>T​(p.Thr4525Ile) 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 benign outcome for this variant. 13/22 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. T4525A) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SACS NM_014363.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.32
• 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=0.25478703).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SACS	NM_014363.6	c.13574C>T	p.Thr4525Ile	missense_variant	Exon 10 of 10	ENST00000382292.9	NP_055178.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SACS	ENST00000382292.9	c.13574C>T	p.Thr4525Ile	missense_variant	Exon 10 of 10	5	NM_014363.6	ENSP00000371729.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	0.0094	T
BayesDel_noAF	Benign	-0.22
CADD	Benign	21
DANN	Benign	0.91
DEOGEN2	Benign	0.33	.;T
Eigen	Benign	-0.11
Eigen_PC	Benign	0.10
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.91	D;D
M_CAP	Benign	0.030	D
MetaRNN	Benign	0.25	T;T
MetaSVM	Benign	-0.53	T
MutationAssessor	Benign	-0.14	.;N
PhyloP100		7.3
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-1.1	N;N
REVEL	Uncertain	0.37
Sift	Benign	0.25	T;T
Sift4G	Benign	0.32	T;T
Polyphen		0.18	.;B
Vest4		0.17
MutPred		0.47		.;Gain of catalytic residue at L4526 (P = 0);
MVP		0.85
ClinPred		0.84	D
GERP RS		5.8
Varity_R		0.47
gMVP		0.43
Mutation Taster		=57/43	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: rs750412600; hg19: chr13-23904441;