rs1555625363

Variant names:

• chr16-89932649-C-T
• rs1555625363
• NM_006086.4:c.136C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP2 PP3_Moderate PP5

The NM_006086.4(TUBB3):​c.136C>T​(p.Arg46Trp) 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R46Q) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TUBB3 NM_006086.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:5 U:1
• Conservation: PhyloP100: 0.00100
• Publications: 0 publications found

Genes affected

TUBB3 (HGNC:20772): (tubulin beta 3 class III) This gene encodes a class III 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 primarily expressed in neurons and may be involved in neurogenesis and axon guidance and maintenance. Mutations in this gene are the cause of congenital fibrosis of the extraocular muscles type 3. Alternate splicing results in multiple transcript variants. A pseudogene of this gene is found on chromosome 6. [provided by RefSeq, Oct 2010]

TUBB3 Gene-Disease associations (from GenCC):

• complex cortical dysplasia with other brain malformations 1

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae), Illumina
• fibrosis of extraocular muscles, congenital, 3A, with or without extraocular involvement

  Inheritance: AD Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• congenital fibrosis of extraocular muscles

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• tubulinopathy-associated dysgyria

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000198211 (HGNC:):

ACMG classification

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

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the TUBB3 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 45 curated pathogenic missense variants (we use a threshold of 10). The gene has 6 curated benign missense variants. Gene score misZ: 4.5786 (above the threshold of 3.09). Trascript score misZ: 5.665 (above the threshold of 3.09). GenCC associations: The gene is linked to fibrosis of extraocular muscles, congenital, 3A, with or without extraocular involvement, tubulinopathy-associated dysgyria, congenital fibrosis of extraocular muscles, complex cortical dysplasia with other brain malformations 1.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.849
• PP5: Variant 16-89932649-C-T is Pathogenic according to our data. Variant chr16-89932649-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 438582.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006086.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TUBB3	NM_006086.4	MANE Select	c.136C>T	p.Arg46Trp	missense	Exon 2 of 4	NP_006077.2
	TUBB3	NM_001197181.2		c.-81C>T		5_prime_UTR	Exon 2 of 4	NP_001184110.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TUBB3	ENST00000315491.12	TSL:1 MANE Select	c.136C>T	p.Arg46Trp	missense	Exon 2 of 4	ENSP00000320295.7
	ENSG00000198211	ENST00000556922.1	TSL:2	c.1177C>T	p.Arg393Trp	missense	Exon 3 of 5	ENSP00000451560.1
	TUBB3	ENST00000557262.5	TSL:1	n.*119C>T		non_coding_transcript_exon	Exon 3 of 5	ENSP00000451985.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions as Germline

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
2	1	-	not provided (3)
1	-	-	Complex cortical dysplasia with other brain malformations 1 (1)
1	-	-	Developmental disorder (1)
1	-	-	Fibrosis of extraocular muscles, congenital, 3A, with or without extraocular involvement (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.030
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.36	T
Eigen	Benign	0.18
Eigen_PC	Benign	-0.088
FATHMM_MKL	Benign	0.67	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.29	D
MetaRNN	Pathogenic	0.85	D
MetaSVM	Uncertain	0.49	D
MutationAssessor	Pathogenic	5.1	H
PhyloP100		0.0010
PrimateAI	Pathogenic	0.89	D
PROVEAN	Pathogenic	-6.1	D
REVEL	Uncertain	0.64
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.66
MutPred		0.71		Loss of disorder (P = 0.0674)
MVP		0.84
MPC		2.8
ClinPred		1.0	D
GERP RS		0.52
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.96
gMVP		0.92

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: rs1555625363; hg19: chr16-89999057;