rs1554126924

Positions:

• chr6-3225566-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP2 PP3

The NM_178012.5(TUBB2B):​c.523G>A​(p.Val175Met) 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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 30)
• Consequence: TUBB2B NM_178012.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.75

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_178012.5
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TUBB2B. . Gene score misZ 5.1195 (greater than the threshold 3.09). Trascript score misZ 6.9522 (greater than threshold 3.09). GenCC has associacion of gene with tubulinopathy-associated dysgyria, congenital fibrosis of extraocular muscles, cerebellar ataxia, intellectual disability, and dysequilibrium, complex cortical dysplasia with other brain malformations 7, complex cortical dysplasia with other brain malformations.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.768

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TUBB2B	NM_178012.5	c.523G>A	p.Val175Met	missense_variant	4/4	ENST00000259818.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TUBB2B	ENST00000259818.8	c.523G>A	p.Val175Met	missense_variant	4/4	1	NM_178012.5	P1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 30

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Sep 21, 2015

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.070
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.44	T
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Uncertain	0.23	D
MetaRNN	Pathogenic	0.77	D
MetaSVM	Uncertain	0.27	D
MutationAssessor	Pathogenic	3.3	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.85	D
PROVEAN	Uncertain	-2.4	N
REVEL	Pathogenic	0.71
Sift4G	Uncertain	0.048	D
Polyphen		1.0	D
Vest4		0.60
MutPred		0.78		Loss of methylation at K174 (P = 0.0436);
MVP		0.79
ClinPred		0.99	D
GERP RS		5.2
Varity_R		0.82
gMVP		0.94

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: rs1554126924; hg19: chr6-3225800;