chr1-235380069-CG-C

Position:

• chr1-235380069-CG-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_003193.5(TBCE):​c.22del​(p.Asp8MetfsTer30) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,410 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TBCE NM_003193.5 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: -0.122

Genes affected

TBCE (HGNC:11582): (tubulin folding cofactor E) Cofactor E 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. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.987 CDS is truncated, and there are 3 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-235380069-CG-C is Pathogenic according to our data. Variant chr1-235380069-CG-C is described in ClinVar as [Pathogenic]. Clinvar id is 2870059.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TBCE	NM_003193.5	c.22del	p.Asp8MetfsTer30	frameshift_variant	2/17	ENST00000642610.2	NP_003184.1
TBCE	NM_001287801.2	c.22del	p.Asp8MetfsTer30	frameshift_variant	2/18		NP_001274730.1
TBCE	NM_001079515.3	c.22del	p.Asp8MetfsTer30	frameshift_variant	2/17		NP_001072983.1
TBCE	NM_001287802.2	c.-289del		5_prime_UTR_variant	2/16		NP_001274731.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TBCE	ENST00000642610.2	c.22del	p.Asp8MetfsTer30	frameshift_variant	2/17		NM_003193.5	ENSP00000494796	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461410 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727028

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 28, 2023

This sequence change creates a premature translational stop signal (p.Asp8Metfs*30) in the TBCE gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in TBCE are known to be pathogenic (PMID: 27666369, 34134906, 34356170). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TBCE-related conditions. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs780909684; hg19: chr1-235543384;