15-42777121-A-C

Position:

• chr15-42777121-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_173500.4(TTBK2):​c.1319T>G​(p.Val440Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. 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. V440M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TTBK2 NM_173500.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.61

Genes affected

TTBK2 (HGNC:19141): (tau tubulin kinase 2) This gene encodes a serine-threonine kinase that putatively phosphorylates tau and tubulin proteins. Mutations in this gene cause spinocerebellar ataxia type 11 (SCA11); a neurodegenerative disease characterized by progressive ataxia and atrophy of the cerebellum and brainstem. [provided by RefSeq, Aug 2009]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.23865348).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTBK2	NM_173500.4	c.1319T>G	p.Val440Gly	missense_variant	12/15	ENST00000267890.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTBK2	ENST00000267890.11	c.1319T>G	p.Val440Gly	missense_variant	12/15	5	NM_173500.4	P1
TTBK2	ENST00000567840.5	c.1319T>G	p.Val440Gly	missense_variant	12/12	1
TTBK2	ENST00000567274.5	c.1214T>G	p.Val405Gly	missense_variant	11/11	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461882 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727242

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Jan 07, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.26
BayesDel_addAF	Benign	-0.099	T
BayesDel_noAF	Benign	-0.38
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.46	T;T;.;T
Eigen	Benign	-0.0092
Eigen_PC	Benign	0.18
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.83	T;T;D;D
M_CAP	Benign	0.026	D
MetaRNN	Benign	0.24	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.0	L;.;L;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.39	T
PROVEAN	Benign	-2.1	N;.;N;N
REVEL	Benign	0.10
Sift	Uncertain	0.016	D;.;D;D
Sift4G	Benign	0.51	T;T;T;T
Polyphen		0.018	B;B;B;.
Vest4		0.51
MutPred		0.34		Loss of stability (P = 0.0014);.;Loss of stability (P = 0.0014);.;
MVP		0.18
MPC		0.75
ClinPred		0.87	D
GERP RS		4.6
Varity_R		0.25
gMVP		0.33

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: rs1555422978; hg19: chr15-43069319;