chr20-59022855-T-C

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The NM_030773.4(TUBB1):​c.68T>C​(p.Met23Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000793 in 1,614,092 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000082 ( 0 hom. )

Consequence

TUBB1
NM_030773.4 missense

Scores

1
2
16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.99
Variant links:
Genes affected
TUBB1 (HGNC:16257): (tubulin beta 1 class VI) This gene encodes a member of the beta tubulin protein family. Beta tubulins are one of two core protein families (alpha and beta tubulins) that heterodimerize and assemble to form microtubules. This protein is specifically expressed in platelets and megakaryocytes and may be involved in proplatelet production and platelet release. A mutations in this gene is associated with autosomal dominant macrothrombocytopenia. Two pseudogenes of this gene are found on chromosome Y.[provided by RefSeq, Jul 2010]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.17314324).
BS2
High AC in GnomAd4 at 8 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TUBB1NM_030773.4 linkc.68T>C p.Met23Thr missense_variant Exon 2 of 4 ENST00000217133.2 NP_110400.1 Q9H4B7
TUBB1XM_017028085.2 linkc.2T>C p.Met1? start_lost Exon 2 of 4 XP_016883574.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TUBB1ENST00000217133.2 linkc.68T>C p.Met23Thr missense_variant Exon 2 of 4 1 NM_030773.4 ENSP00000217133.1 Q9H4B7

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152090
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000966
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000398
AC:
10
AN:
251384
Hom.:
0
AF XY:
0.0000294
AC XY:
4
AN XY:
135872
show subpopulations
Gnomad AFR exome
AF:
0.000123
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000528
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000821
AC:
120
AN:
1461884
Hom.:
0
Cov.:
31
AF XY:
0.0000853
AC XY:
62
AN XY:
727240
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000224
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:
0.000105
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000526
AC:
8
AN:
152208
Hom.:
0
Cov.:
31
AF XY:
0.0000403
AC XY:
3
AN XY:
74428
show subpopulations
Gnomad4 AFR
AF:
0.0000963
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000588
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000302
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000576
AC:
7
EpiCase
AF:
0.000109
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Jul 01, 2019
CeGaT Center for Human Genetics Tuebingen
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jun 13, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 23 of the TUBB1 protein (p.Met23Thr). This variant is present in population databases (rs374942824, gnomAD 0.01%). This missense change has been observed in individual(s) with an unspecified bleeding disorder (PMID: 32935436). ClinVar contains an entry for this variant (Variation ID: 871094). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt TUBB1 protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Thrombocytopenia;C1458140:Abnormal bleeding Uncertain:1
May 01, 2020
Birmingham Platelet Group; University of Birmingham
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: research

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.30
CADD
Uncertain
24
DANN
Uncertain
0.98
DEOGEN2
Benign
0.047
T
Eigen
Benign
-0.37
Eigen_PC
Benign
-0.13
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Benign
0.60
T
M_CAP
Benign
0.035
D
MetaRNN
Benign
0.17
T
MetaSVM
Benign
-0.95
T
MutationAssessor
Benign
-2.4
N
PrimateAI
Benign
0.39
T
PROVEAN
Benign
0.12
N
REVEL
Benign
0.25
Sift
Pathogenic
0.0
D
Sift4G
Benign
0.38
T
Polyphen
0.0
B
Vest4
0.30
MVP
0.69
MPC
0.22
ClinPred
0.14
T
GERP RS
4.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.66
gMVP
0.61

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs374942824; hg19: chr20-57597910; COSMIC: COSV53887009; COSMIC: COSV53887009; API