19-6495688-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2PP2PP3_Strong

The NM_006087.4(TUBB4A):​c.811G>A​(p.Ala271Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,724 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

TUBB4A
NM_006087.4 missense

Scores

7
8
3

Clinical Significance

Uncertain significance criteria provided, single submitter P:1U:1

Conservation

PhyloP100: 7.69
Variant links:
Genes affected
TUBB4A (HGNC:20774): (tubulin beta 4A class IVa) This gene encodes a member of the beta tubulin family. Beta tubulins are one of two core protein families (alpha and beta tubulins) that heterodimerize and assemble to form microtubules. Mutations in this gene cause hypomyelinating leukodystrophy-6 and autosomal dominant torsion dystonia-4. Alternate splicing results in multiple transcript variants encoding different isoforms. A pseudogene of this gene is found on chromosome X. [provided by RefSeq, Jan 2014]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TUBB4A. . Gene score misZ 4.2623 (greater than the threshold 3.09). Trascript score misZ 5.1229 (greater than threshold 3.09). GenCC has associacion of gene with torsion dystonia 4, TUBB4A-related neurologic disorder, hypomyelinating leukodystrophy 6.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.94

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TUBB4ANM_006087.4 linkuse as main transcriptc.811G>A p.Ala271Thr missense_variant 4/4 ENST00000264071.7 NP_006078.2 P04350

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TUBB4AENST00000264071.7 linkuse as main transcriptc.811G>A p.Ala271Thr missense_variant 4/41 NM_006087.4 ENSP00000264071.1 P04350
TUBB4AENST00000594276.5 linkuse as main transcriptc.*34G>A downstream_gene_variant 4 ENSP00000472481.2 M0R2D3

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000399
AC:
1
AN:
250528
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135624
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461724
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727194
show subpopulations
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:
0.0000232
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
8.99e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Torsion dystonia 4 Pathogenic:1
Pathogenic, no assertion criteria providedliterature onlyOMIMApr 01, 2013- -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingGeneDxJun 20, 2024Reported in a patient with spasmodic dystonia, oromandibular dystonia, and dyskinesia in published literature (PMID: 23595291); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 30079973, 23595291, 35260199, 29127012) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.50
BayesDel_addAF
Pathogenic
0.37
D
BayesDel_noAF
Pathogenic
0.29
CADD
Pathogenic
29
DANN
Benign
0.93
DEOGEN2
Uncertain
0.61
D
Eigen
Uncertain
0.20
Eigen_PC
Benign
0.18
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.96
D
M_CAP
Pathogenic
0.91
D
MetaRNN
Pathogenic
0.94
D
MetaSVM
Uncertain
0.21
D
MutationAssessor
Pathogenic
4.0
H
PrimateAI
Uncertain
0.78
T
PROVEAN
Uncertain
-3.1
D
REVEL
Pathogenic
0.88
Sift4G
Uncertain
0.035
D
Polyphen
0.51
P
Vest4
0.83
MutPred
0.80
Loss of catalytic residue at A271 (P = 0.1055);
MVP
0.82
MPC
1.5
ClinPred
1.0
D
GERP RS
3.7
Varity_R
0.88
gMVP
0.98

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: rs587777074; hg19: chr19-6495699; API