chr9-132349365-C-A

Variant names:

• chr9-132349365-C-A
• rs756600708
• NM_015046.7:c.64G>T

Variant summary

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

The NM_015046.7(SETX):​c.64G>T​(p.Ala22Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A22T) has been classified as Benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SETX NM_015046.7 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.74
• Publications: 0 publications found

Genes affected

SETX (HGNC:445): (senataxin) This gene encodes a protein named for its homology to the Sen1p protein of fungi which has RNA helicase activity encoded by a domain at the C-terminal end of the protein. The protein encoded by this gene contains a DNA/RNA helicase domain at its C-terminal end which suggests that it may be involved in both DNA and RNA processing. Mutations in this gene have been associated with ataxia-ocular apraxia-2 (AOA2) and an autosomal dominant form of juvenile amyotrophic lateral sclerosis (ALS4). [provided by RefSeq, Jul 2008]

SETX Gene-Disease associations (from GenCC):

• amyotrophic lateral sclerosis type 4

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae)
• distal hereditary motor neuropathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 2

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SETX	NM_015046.7	c.64G>T	p.Ala22Ser	missense_variant	Exon 3 of 26	ENST00000224140.6	NP_055861.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SETX	ENST00000224140.6	c.64G>T	p.Ala22Ser	missense_variant	Exon 3 of 26	1	NM_015046.7	ENSP00000224140.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 2;C1865409:Amyotrophic lateral sclerosis type 4 Uncertain:1

Dec 29, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine with serine at codon 22 of the SETX protein (p.Ala22Ser). The alanine residue is moderately conserved and there is a moderate physicochemical difference between alanine and serine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with SETX-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Benign	-0.090
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Benign	0.29	T
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.72	T
M_CAP	Uncertain	0.29	D
MetaRNN	Uncertain	0.72	D
MetaSVM	Uncertain	0.67	D
MutationAssessor	Benign	1.0	L
PhyloP100		2.7
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-0.97	N
REVEL	Uncertain	0.42
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.039	D
Polyphen		1.0	D
Vest4		0.54
MutPred		0.26		Gain of disorder (P = 0.0198);
MVP		0.85
MPC		0.42
ClinPred		0.81	D
GERP RS		5.4
Varity_R		0.13
gMVP		0.16
Mutation Taster		=73/27	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: rs756600708; hg19: chr9-135224752;