17-82800926-C-T

Position:

chr17-82800926-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2PM5PP3_ModeratePP5

The NM_005993.5(TBCD):c.880C>T(p.Arg294Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,611,742 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R294Q) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000069 ( 0 hom. )

Consequence

TBCD
NM_005993.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 2.68

Variant links:

Genes affected

TBCD (HGNC:11581): (tubulin folding cofactor D) Cofactor D is one of four proteins (cofactors A, D, E, and C) involved in the pathway leading to correctly folded beta-tubulin from folding intermediates. Cofactors A and D are believed to play a role in capturing and stabilizing beta-tubulin intermediates in a quasi-native confirmation. Cofactor E binds to the cofactor D/beta-tubulin complex; interaction with cofactor C then causes the release of beta-tubulin polypeptides that are committed to the native state. [provided by RefSeq, Jul 2008]

TBCD links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr17-82800927-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 449795.Status of the report is criteria_provided_single_submitter, 1 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.888

PP5

Variant 17-82800926-C-T is Pathogenic according to our data. Variant chr17-82800926-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 423874.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TBCD	NM_005993.5 linkuse as main transcript	c.880C>T	p.Arg294Trp	missense_variant	9/39	ENST00000355528.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TBCD	ENST00000355528.9 linkuse as main transcript	c.880C>T	p.Arg294Trp	missense_variant	9/39	1	NM_005993.5	P1	Q9BTW9-1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152074

Hom.:

Cov.:

show subpopulations

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000809

AC:

AN:

247086

Hom.:

AF XY:

0.00000744

AC XY:

AN XY:

134330

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000328

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000894

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000685

AC:

AN:

1459668

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

726160

show subpopulations

Gnomad4 AFR exome

AF:

0.0000300

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000253

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152074

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74282

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000312

Hom.:

Bravo

AF:

0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:1Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 15, 2023	ClinVar contains an entry for this variant (Variation ID: 423874). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TBCD protein function. For these reasons, this variant has been classified as Pathogenic. This missense change has been observed in individual(s) with progressive early-onset encephalopathy with brain atrophy and thin corpus callosum (PMID: 32705489). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. This variant is present in population databases (no rsID available, gnomAD 0.003%). This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 294 of the TBCD protein (p.Arg294Trp). -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Mar 06, 2017	The R294W variant in the TBCD gene has not been reported previously as a pathogenic variant, nor as a benign variant, to our knowledge. The R294W variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The R294W variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species. In silico analysis predicts this variant is probably damaging to the protein structure/function. We interpret R294W as a variant of uncertain significance. -

Early-onset progressive diffuse brain atrophy-microcephaly-muscle weakness-optic atrophy syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.44

BayesDel_addAF

Pathogenic

0.24

BayesDel_noAF

Pathogenic

0.21

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.47

T;.

Eigen

Pathogenic

0.73

Eigen_PC

Uncertain

0.65

FATHMM_MKL

Uncertain

0.92

LIST_S2

Uncertain

0.97

D;D

M_CAP

Pathogenic

0.40

MetaRNN

Pathogenic

0.89

D;D

MetaSVM

Uncertain

0.51

MutationAssessor

Pathogenic

3.7

H;.

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.63

PROVEAN

Pathogenic

-5.7

D;.

REVEL

Pathogenic

0.69

Sift

Uncertain

0.0020

D;.

Sift4G

Uncertain

0.0040

D;D

Polyphen

1.0

D;.

Vest4

0.86

MutPred

0.60

Gain of catalytic residue at L292 (P = 0.0037);Gain of catalytic residue at L292 (P = 0.0037);

MVP

0.92

MPC

1.0

ClinPred

1.0

GERP RS

5.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.8

Varity_R

0.44

gMVP

0.73

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over