rs797046075

Variant names:

• chr6-3225797-C-T
• rs797046075
• NM_178012.5:c.292G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2 PP2 PP3_Strong PP5

The NM_178012.5(TUBB2B):​c.292G>A​(p.Gly98Arg) 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. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0 (0 hom., cov: 31)
  • Failed GnomAD Quality Control
• Consequence: TUBB2B NM_178012.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4 U:1
• Conservation: PhyloP100: 7.78
• Publications: 3 publications found

Genes affected

TUBB2B (HGNC:30829): (tubulin beta 2B class IIb) The protein encoded by this gene is a beta isoform of tubulin, which binds GTP and is a major component of microtubules. This gene is highly similar to TUBB2A and TUBB2C. Defects in this gene are a cause of asymmetric polymicrogyria. [provided by RefSeq, Mar 2010]

TUBB2B Gene-Disease associations (from GenCC):

• complex cortical dysplasia with other brain malformations

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• complex cortical dysplasia with other brain malformations 7

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet
• congenital fibrosis of extraocular muscles

  Inheritance: AD Classification: SUPPORTIVE, LIMITED Submitted by: Orphanet, Genomics England PanelApp
• tubulinopathy-associated dysgyria

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• cerebellar ataxia, intellectual disability, and dysequilibrium

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the TUBB2B 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 2 curated benign missense variants. Gene score misZ: 5.1195 (above the threshold of 3.09). Trascript score misZ: 6.9522 (above the threshold of 3.09). GenCC associations: The gene is linked to tubulinopathy-associated dysgyria, congenital fibrosis of extraocular muscles, complex cortical dysplasia with other brain malformations 7, complex cortical dysplasia with other brain malformations, cerebellar ataxia, intellectual disability, and dysequilibrium.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant 6-3225797-C-T is Pathogenic according to our data. Variant chr6-3225797-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 212497.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_178012.5. 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
	TUBB2B	NM_178012.5	MANE Select	c.292G>A	p.Gly98Arg	missense	Exon 4 of 4	NP_821080.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TUBB2B	ENST00000259818.8	TSL:1 MANE Select	c.292G>A	p.Gly98Arg	missense	Exon 4 of 4	ENSP00000259818.6
	TUBB2B	ENST00000473006.1	TSL:3	n.409G>A		non_coding_transcript_exon	Exon 4 of 4
	TUBB2B	ENST00000680070.1		n.1222G>A		non_coding_transcript_exon	Exon 3 of 3

Frequencies

GnomAD3 genomes AF: 0.00 AC: 0 AN: 151710 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 34

GnomAD4 genome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 151710 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74118

African (AFR) AF: 0.00 AC: 0 AN: 41102

American (AMR) AF: 0.00 AC: 0 AN: 15258

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5156

South Asian (SAS) AF: 0.00 AC: 0 AN: 4800

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10598

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68012

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions as Germline

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
3	-	-	Complex cortical dysplasia with other brain malformations 7 (3)
1	1	-	not provided (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.54	D
Eigen	Pathogenic	0.70
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.53	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.86	D
MutationAssessor	Pathogenic	4.6	H
PhyloP100		7.8
PrimateAI	Pathogenic	0.94	D
PROVEAN	Pathogenic	-4.6	D
REVEL	Pathogenic	0.84
Sift4G	Uncertain	0.033	D
Polyphen		0.93	P
Vest4		0.99
MutPred		0.92		Loss of ubiquitination at K103 (P = 0.0455)
MVP		0.82
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.83
gMVP		0.99
Mutation Taster		=14/86	disease causing (ClinVar)

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: rs797046075; hg19: chr6-3226031; COSMIC: COSV52534455;