11-66710947-G-A

Variant names:

• chr11-66710947-G-A
• rs373123134
• NM_006946.4:c.855C>T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_006946.4(SPTBN2):​c.855C>T​(p.Ala285Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A285A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SPTBN2 NM_006946.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.418
• Publications: 0 publications found

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]

SPTBN2 Gene-Disease associations (from GenCC):

• autosomal recessive spinocerebellar ataxia 14

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P, Orphanet
• spinocerebellar ataxia type 5

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Illumina, G2P

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.39).
• BP7: Synonymous conserved (PhyloP=-0.418 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006946.4. 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
	SPTBN2	NM_006946.4	MANE Select	c.855C>T	p.Ala285Ala	synonymous	Exon 9 of 38	NP_008877.2
	SPTBN2	NM_001411025.1		c.876C>T	p.Ala292Ala	synonymous	Exon 7 of 36	NP_001397954.1
	SPTBN2	NM_001437541.1		c.855C>T	p.Ala285Ala	synonymous	Exon 8 of 37	NP_001424470.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SPTBN2	ENST00000533211.6	TSL:5 MANE Select	c.855C>T	p.Ala285Ala	synonymous	Exon 9 of 38	ENSP00000432568.1
	SPTBN2	ENST00000309996.7	TSL:1	c.855C>T	p.Ala285Ala	synonymous	Exon 8 of 37	ENSP00000311489.2
	SPTBN2	ENST00000617502.5	TSL:5	c.876C>T	p.Ala292Ala	synonymous	Exon 7 of 36	ENSP00000482000.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461880 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727242

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112006

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.39
CADD	Benign	7.5
DANN	Benign	0.68
PhyloP100		-0.42

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: rs373123134; hg19: chr11-66478418;