19-6496032-C-T

Variant names:

• chr19-6496032-C-T
• rs587777429
• NM_006087.4:c.467G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PM5 PP3_Moderate

The NM_006087.4(TUBB4A):​c.467G>A​(p.Arg156His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R156C) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TUBB4A NM_006087.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.78
• Publications: 10 publications found

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]

TUBB4A Gene-Disease associations (from GenCC):

• hypomyelinating leukodystrophy 6

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Labcorp Genetics (formerly Invitae), Illumina
• TUBB4A-related neurologic disorder

  Inheritance: AD Classification: DEFINITIVE, MODERATE Submitted by: Ambry Genetics, ClinGen
• torsion dystonia 4

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr19-6496033-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2195059.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.881

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006087.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TUBB4A	NM_006087.4	MANE Select	c.467G>A	p.Arg156His	missense	Exon 4 of 4	NP_006078.2
	TUBB4A	NM_001289123.2		c.620G>A	p.Arg207His	missense	Exon 5 of 5	NP_001276052.1	M0QZL7
	TUBB4A	NM_001289127.2		c.602G>A	p.Arg201His	missense	Exon 5 of 5	NP_001276056.1	M0R278

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TUBB4A	ENST00000264071.7	TSL:1 MANE Select	c.467G>A	p.Arg156His	missense	Exon 4 of 4	ENSP00000264071.1	P04350
	TUBB4A	ENST00000598635.2	TSL:4	c.620G>A	p.Arg207His	missense	Exon 5 of 5	ENSP00000470627.2	M0QZL7
	TUBB4A	ENST00000597686.6	TSL:4	c.602G>A	p.Arg201His	missense	Exon 5 of 5	ENSP00000472375.2	M0R278

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461890 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.0000187 AC: 1 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Benign	-0.090
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.25	T
Eigen	Uncertain	0.53
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D
M_CAP	Pathogenic	0.58	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Uncertain	0.078	D
MutationAssessor	Pathogenic	3.1	M
PhyloP100		7.8
PrimateAI	Pathogenic	0.92	D
PROVEAN	Uncertain	-3.6	D
REVEL	Pathogenic	0.71
Sift4G	Uncertain	0.032	D
Polyphen		0.71	P
Vest4		0.72
MutPred		0.70		Gain of methylation at K154 (P = 0.0676)
MVP		0.84
MPC		2.9
ClinPred		0.99	D
GERP RS		4.0
Varity_R		0.88
gMVP		0.96
Mutation Taster		=23/77	disease causing

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

Other links and lift over

dbSNP: rs587777429; hg19: chr19-6496043; COSMIC: COSV51155246; COSMIC: COSV51155246;