Genetic Variant TTBK2:p.Glu691Lys (chr15-42753175-C-T) – ACMG Classification: Benign (-7 pts)

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBS1_SupportingBS2

The NM_173500.4(TTBK2):c.2071G>A(p.Glu691Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000181 in 1,606,244 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

TTBK2
NM_173500.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 5.75

Publications

0 publications found

Variant links:

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]

TTBK2 Gene-Disease associations (from GenCC):

spinocerebellar ataxia type 11
Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet

TTBK2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.21872947).

BS1

Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.000131 (20/152198) while in subpopulation AMR AF = 0.000327 (5/15278). AF 95% confidence interval is 0.000185. There are 0 homozygotes in GnomAd4. There are 11 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High AC in GnomAd4 at 20 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_173500.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTBK2	NM_173500.4	MANE Select	c.2071G>A	p.Glu691Lys	missense	Exon 14 of 15	NP_775771.3

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTBK2	ENST00000267890.11	TSL:5 MANE Select	c.2071G>A	p.Glu691Lys	missense	Exon 14 of 15	ENSP00000267890.6
TTBK2	ENST00000903061.1		c.2071G>A	p.Glu691Lys	missense	Exon 14 of 15	ENSP00000573120.1
TTBK2	ENST00000903062.1		c.2005G>A	p.Glu669Lys	missense	Exon 13 of 14	ENSP00000573121.1

Frequencies

GnomAD3 genomes

AF:

0.000131

AC:

AN:

152198

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000314

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000327

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000956

GnomAD2 exomes

AF:

0.0000166

AC:

AN:

240630

AF XY:

0.00000766

show subpopulations

Gnomad AFR exome

AF:

0.000261

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000619

AC:

AN:

1454046

Hom.:

Cov.:

AF XY:

0.00000553

AC XY:

AN XY:

723212

show subpopulations

African (AFR)

AF:

0.000152

AC:

AN:

32872

American (AMR)

AF:

0.0000470

AC:

AN:

42562

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25668

East Asian (EAS)

AF:

0.00

AC:

AN:

39688

South Asian (SAS)

AF:

0.00

AC:

AN:

84342

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53284

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5710

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1109916

Other (OTH)

AF:

0.0000333

AC:

AN:

60004

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.514

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000131

AC:

AN:

152198

Hom.:

Cov.:

AF XY:

0.000148

AC XY:

AN XY:

74364

show subpopulations

African (AFR)

AF:

0.000314

AC:

AN:

41440

American (AMR)

AF:

0.000327

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5198

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68042

Other (OTH)

AF:

0.000956

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.468

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.000170

ESP6500AA

AF:

0.000268

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000165

AC:

ClinVar

ClinVar submissions as Germline

Significance:Uncertain significance

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Inborn genetic diseases (1)

not specified (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Benign

-0.18

BayesDel_noAF

Benign

-0.15

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.10

Eigen

Uncertain

0.48

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Uncertain

0.97

LIST_S2

Uncertain

0.90

M_CAP

Benign

0.018

MetaRNN

Benign

0.22

MetaSVM

Benign

-0.97

MutationAssessor

Uncertain

2.1

PhyloP100

5.8

PrimateAI

Uncertain

0.55

PROVEAN

Benign

-0.61

REVEL

Benign

0.21

Sift

Uncertain

0.0020

Sift4G

Benign

0.39

Polyphen

0.80

Vest4

0.48

MVP

0.29

MPC

0.64

ClinPred

0.45

GERP RS

5.8

Varity_R

0.21

gMVP

0.53

Mutation Taster

=66/34

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over