1-235380150-G-A

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PVS1PM2PP3_StrongPP5

The NM_003193.5(TBCE):c.100+1G>A variant causes a splice donor change. The variant allele was found at a frequency of 0.0000685 in 1,590,918 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000087 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000067 ( 0 hom. )

Consequence

TBCE
NM_003193.5 splice_donor

Scores

Splicing: ADA: 1.000

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:6U:1O:1

Conservation

PhyloP100: 4.66

Variant links:

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]

TBCE links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 15 ACMG points.

PVS1

Splicing variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 7.5, offset of -34, new splice context is: acaGTacgt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 1-235380150-G-A is Pathogenic according to our data. Variant chr1-235380150-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 631595.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=1, Pathogenic=2, not_provided=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	MANE
TBCE	NM_003193.5 linkuse as main transcript	c.100+1G>A	splice_donor_variant	ENST00000642610.2
TBCE	NM_001079515.3 linkuse as main transcript	c.100+1G>A	splice_donor_variant
TBCE	NM_001287801.2 linkuse as main transcript	c.100+1G>A	splice_donor_variant
TBCE	NM_001287802.2 linkuse as main transcript	c.-211+1G>A	splice_donor_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TBCE	ENST00000642610.2 linkuse as main transcript	c.100+1G>A		splice_donor_variant			NM_003193.5	P1	Q15813-1

Frequencies

GnomAD3 genomes

AF:

0.0000871

AC:

AN:

149328

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:

0.000193

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000800

AC:

AN:

249900

Hom.:

AF XY:

0.0000666

AC XY:

AN XY:

135156

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000159

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000666

AC:

AN:

1441590

Hom.:

Cov.:

AF XY:

0.0000682

AC XY:

AN XY:

717982

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000225

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000830

Gnomad4 OTH exome

AF:

0.0000505

GnomAD4 genome

AF:

0.0000871

AC:

AN:

149328

Hom.:

Cov.:

AF XY:

0.0000964

AC XY:

AN XY:

72632

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:

0.000193

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000158

Hom.:

Bravo

AF:

0.0000642

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000988

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:6Uncertain:1Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Apr 01, 2023	TBCE: PVS1, PM2 -
Likely pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 14, 2024	This sequence change affects a donor splice site in intron 2 of the TBCE gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in TBCE are known to be pathogenic (PMID: 27666369, 34134906, 34356170). This variant is present in population databases (rs200356271, gnomAD 0.02%). Disruption of this splice site has been observed in individual(s) with TBCE-related conditions (PMID: 35432193). ClinVar contains an entry for this variant (Variation ID: 631595). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 12, 2023	Canonical splice site variant predicted to result in a null allele in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 35432193) -

Autosomal recessive Kenny-Caffey syndrome

Pathogenic:1Other:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Centre for Mendelian Genomics, University Medical Centre Ljubljana	Jan 15, 2020	This variant was classified as: Likely pathogenic. The following ACMG criteria were applied in classifying this variant: PVS1,PM2. -
not provided, no classification provided	phenotyping only	Department of Developmental Neurology, Medical University of Gdańsk	-	- -

TBCE-related disorder

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Aug 29, 2022

Variant summary: TBCE c.100+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: four predict the variant abolishes a 5' splicing donor site, while three predict the variant creates a 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 8e-05 in 249900 control chromosomes (gnomAD). This frequency allows no conclusions about variant significance. The variant, c.100+1G>A, has been reported in the literature in a homozygous individual affected with TBCE-Related Disorder (Globa_2022). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014, and reported the variant with conflicting assessments (VUS (n=2), likely pathogenic (n=2)). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Disorder of sexual differentiation

Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

Human Developmental Genetics, Institut Pasteur

Aug 17, 2021

- -

Hypoparathyroidism-retardation-dysmorphism syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Aug 23, 2017

The TBCE c.100+1G>A variant occurs in a canonical splice site (donor) and is therefore predicted to disrupt or distort the normal gene product. It was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018) and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score for this variant, it could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene and cDNA change. No publications were found based on this search. Due to the potential impact of splice donor variants and the lack of clarifying evidence, this variant is classified as a variant of unknown significance but suspicious for pathogenicity for hypoparathyroidism-retardation-dysmorphism syndrome. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.44

BayesDel_noAF

Pathogenic

0.22

Cadd

Pathogenic

Dann

Uncertain

0.99

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.84

FATHMM_MKL

Uncertain

0.94

MutationTaster

Benign

1.0

D;D;D

GERP RS

5.5

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.94

SpliceAI score (max)

1.0

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.96

Position offset: -35

DS_DL_spliceai

1.0

Position offset: -1

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