20-59019564-C-G

Position:

• chr20-59019564-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_030773.4(TUBB1):​c.42C>G​(p.Asn14Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: TUBB1 NM_030773.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.38

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.922

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TUBB1	NM_030773.4	c.42C>G	p.Asn14Lys	missense_variant	1/4	ENST00000217133.2	NP_110400.1
TUBB1	XM_017028085.2	c.-10+3019C>G		intron_variant			XP_016883574.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TUBB1	ENST00000217133.2	c.42C>G	p.Asn14Lys	missense_variant	1/4	1	NM_030773.4	ENSP00000217133.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

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

Labcorp Genetics (formerly Invitae), Labcorp

Sep 01, 2023

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. 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 expected to disrupt TUBB1 protein function. This variant has not been reported in the literature in individuals affected with TUBB1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 14 of the TUBB1 protein (p.Asn14Lys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Uncertain	0.084	D
BayesDel_noAF	Benign	-0.12
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.45	T
Eigen	Pathogenic	0.80
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.97	D
M_CAP	Uncertain	0.13	D
MetaRNN	Pathogenic	0.92	D
MetaSVM	Uncertain	0.56	D
MutationAssessor	Pathogenic	4.4	H
PrimateAI	Pathogenic	0.81	D
PROVEAN	Benign	-1.7	N
REVEL	Pathogenic	0.69
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.88
MutPred		0.79		Gain of methylation at N14 (P = 0.0082);
MVP		0.93
MPC		0.81
ClinPred		1.0	D
GERP RS		3.5
Varity_R		0.94
gMVP		0.80

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr20-57594619;