rs886041010

Positions:

• chr19-6495768-C-A
• chr19-6495768-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP2 PP3_Strong PP5

The NM_006087.4(TUBB4A):​c.731G>T​(p.Gly244Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TUBB4A NM_006087.4 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1 O:1
• Conservation: PhyloP100: 7.70

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 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, 0.977
• PP5: Variant 19-6495768-C-A is Pathogenic according to our data. Variant chr19-6495768-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 267777.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TUBB4A	NM_006087.4	c.731G>T	p.Gly244Val	missense_variant	4/4	ENST00000264071.7	NP_006078.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TUBB4A	ENST00000264071.7	c.731G>T	p.Gly244Val	missense_variant	4/4	1	NM_006087.4	ENSP00000264071	P1
TUBB4A	ENST00000594276.5	c.419G>T	p.Gly140Val	missense_variant	3/3	4		ENSP00000472481
TUBB4A	ENST00000594075.5			downstream_gene_variant		3		ENSP00000469936
TUBB4A	ENST00000600216.5			downstream_gene_variant		5		ENSP00000470983

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: no assertion criteria provided

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Molecular Genetics laboratory, Necker Hospital

Apr 11, 2023

- -

Hypomyelinating leukodystrophy 6 Other:1

not provided, no classification provided

literature only

GeneReviews

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.46
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.47	T;.
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-7.9	D;.
REVEL	Pathogenic	0.96
Sift4G	Pathogenic	0.0	D;D
Polyphen		0.98	D;.
Vest4		0.96
MutPred		0.83		Loss of methylation at R241 (P = 0.1292);.;
MVP		0.91
MPC		3.1
ClinPred		1.0	D
GERP RS		4.0
Varity_R		0.94
gMVP		1.0

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

Other links and lift over

dbSNP: rs886041010; hg19: chr19-6495779;