15-42753175-C-T

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

8
11

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

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.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTBK2NM_173500.4 linkc.2071G>A p.Glu691Lys missense_variant Exon 14 of 15 ENST00000267890.11 NP_775771.3 Q6IQ55-1Q8IWY7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTBK2ENST00000267890.11 linkc.2071G>A p.Glu691Lys missense_variant Exon 14 of 15 5 NM_173500.4 ENSP00000267890.6 Q6IQ55-1

Frequencies

GnomAD3 genomes
AF:
0.000131
AC:
20
AN:
152198
Hom.:
0
Cov.:
32
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:
4
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:
9
AN:
1454046
Hom.:
0
Cov.:
32
AF XY:
0.00000553
AC XY:
4
AN XY:
723212
show subpopulations
African (AFR)
AF:
0.000152
AC:
5
AN:
32872
American (AMR)
AF:
0.0000470
AC:
2
AN:
42562
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25668
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39688
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84342
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53284
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5710
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1109916
Other (OTH)
AF:
0.0000333
AC:
2
AN:
60004
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.514
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
20
AN:
152198
Hom.:
0
Cov.:
32
AF XY:
0.000148
AC XY:
11
AN XY:
74364
show subpopulations
African (AFR)
AF:
0.000314
AC:
13
AN:
41440
American (AMR)
AF:
0.000327
AC:
5
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68042
Other (OTH)
AF:
0.000956
AC:
2
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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.:
0
Bravo
AF:
0.000170
ESP6500AA
AF:
0.000268
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Sep 02, 2016
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Uncertain:1
Jan 23, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.2071G>A (p.E691K) alteration is located in exon 14 (coding exon 13) of the TTBK2 gene. This alteration results from a G to A substitution at nucleotide position 2071, causing the glutamic acid (E) at amino acid position 691 to be replaced by a lysine (K). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.12
BayesDel_addAF
Benign
-0.18
T
BayesDel_noAF
Benign
-0.15
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.10
T;T
Eigen
Uncertain
0.48
Eigen_PC
Uncertain
0.56
FATHMM_MKL
Uncertain
0.97
D
LIST_S2
Uncertain
0.90
D;D
M_CAP
Benign
0.018
T
MetaRNN
Benign
0.22
T;T
MetaSVM
Benign
-0.97
T
MutationAssessor
Uncertain
2.1
M;.
PhyloP100
5.8
PrimateAI
Uncertain
0.55
T
PROVEAN
Benign
-0.61
N;.
REVEL
Benign
0.21
Sift
Uncertain
0.0020
D;.
Sift4G
Benign
0.39
T;T
Polyphen
0.80
P;.
Vest4
0.48
MVP
0.29
MPC
0.64
ClinPred
0.45
T
GERP RS
5.8
Varity_R
0.21
gMVP
0.53
Mutation Taster
=66/34
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

Publications

Other links and lift over

dbSNP: rs369896751; hg19: chr15-43045373; API