rs797046006

Positions:

• chr11-66715958-T-C

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PM1 PM2 PP2 PP3_Moderate PP5_Very_Strong

The NM_006946.4(SPTBN2):​c.181A>G​(p.Lys61Glu) 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. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K61N) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SPTBN2 NM_006946.4 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.97

Genes affected

SPTBN2 (HGNC:11276): (spectrin beta, non-erythrocytic 2) Spectrins are principle components of a cell's membrane-cytoskeleton and are composed of two alpha and two beta spectrin subunits. The protein encoded by this gene (SPTBN2), is called spectrin beta non-erythrocytic 2 or beta-III spectrin. It is related to, but distinct from, the beta-II spectrin gene which is also known as spectrin beta non-erythrocytic 1 (SPTBN1). SPTBN2 regulates the glutamate signaling pathway by stabilizing the glutamate transporter EAAT4 at the surface of the plasma membrane. Mutations in this gene cause a form of spinocerebellar ataxia, SCA5, that is characterized by neurodegeneration, progressive locomotor incoordination, dysarthria, and uncoordinated eye movements. [provided by RefSeq, Dec 2009]

ACMG classification

Verdict is Pathogenic. Variant got 15 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_006946.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, SPTBN2
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.865
• PP5: Variant 11-66715958-T-C is Pathogenic according to our data. Variant chr11-66715958-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 212300.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SPTBN2	NM_006946.4	c.181A>G	p.Lys61Glu	missense_variant	4/38	ENST00000533211.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SPTBN2	ENST00000533211.6	c.181A>G	p.Lys61Glu	missense_variant	4/38	5	NM_006946.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Sep 08, 2015

The K61E variant in the SPTBN2 gene has not been published as a pathogenic variant, nor has it been reported as a benign polymorphism to our knowledge. The K61E variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The K61E variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species. In silico analysis predicts this variant is probably damaging to the protein structure/function. The K61E variant is a strong candidate for a disease-causing variant, however the possibility it may be a rare benign variant cannot be excluded. -

Cerebellar ataxia Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Feb 12, 2015

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D;D;.;.;.;.
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.87	D;D;D;D;D;D
MetaSVM	Uncertain	0.27	D
MutationAssessor	Pathogenic	3.5	H;H;.;H;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.91	D
PROVEAN	Uncertain	-3.4	D;D;.;D;.;D
REVEL	Pathogenic	0.75
Sift	Pathogenic	0.0	D;D;.;D;.;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D
Polyphen		1.0	D;D;.;.;.;.
Vest4		0.94
MutPred		0.61		Loss of MoRF binding (P = 0.0056);Loss of MoRF binding (P = 0.0056);Loss of MoRF binding (P = 0.0056);Loss of MoRF binding (P = 0.0056);Loss of MoRF binding (P = 0.0056);Loss of MoRF binding (P = 0.0056);
MVP		0.96
MPC		2.2
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.90
gMVP		0.84

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

Publications

LitVar

Other links and lift over

dbSNP: rs797046006; hg19: chr11-66483429;