Genetic Variant TBC1D2B:p.Thr933Ile (chr15-77998254-G-A) – ACMG Classification: Likely_benign (-1 pts)

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2BP4_ModerateBS1_Supporting

The NM_144572.2(TBC1D2B):c.2798C>T(p.Thr933Ile) variant causes a missense change. The variant allele was found at a frequency of 0.000165 in 1,598,072 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00018 ( 0 hom. )

Consequence

TBC1D2B
NM_144572.2 missense

Scores

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 3.96

Variant links:

Genes affected

TBC1D2B (HGNC:29183): (TBC1 domain family member 2B) Predicted to enable GTPase activator activity. Predicted to be involved in activation of GTPase activity and intracellular protein transport. Located in cytosol. [provided by Alliance of Genome Resources, Apr 2022]

TBC1D2B links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.1664786).

BS1

Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.0000394 (6/152224) while in subpopulation NFE AF= 0.0000882 (6/68038). AF 95% confidence interval is 0.0000376. There are 0 homozygotes in gnomad4. There are 4 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TBC1D2B	NM_144572.2 link	c.2798C>T	p.Thr933Ile	missense_variant	Exon 13 of 13	ENST00000300584.8	NP_653173.1	Q9UPU7-1B2RTQ2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TBC1D2B	ENST00000300584.8 link	c.2798C>T	p.Thr933Ile	missense_variant	Exon 13 of 13	5	NM_144572.2	ENSP00000300584.3		Q9UPU7-1

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152224

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:

0.0000882

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000266

AC:

AN:

225336

Hom.:

AF XY:

0.0000247

AC XY:

AN XY:

121650

show subpopulations

Gnomad AFR exome

AF:

0.0000737

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000395

Gnomad OTH exome

AF:

0.000176

GnomAD4 exome

AF:

0.000178

AC:

257

AN:

1445848

Hom.:

Cov.:

AF XY:

0.000176

AC XY:

126

AN XY:

717536

show subpopulations

Gnomad4 AFR exome

AF:

0.0000302

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:

0.000230

Gnomad4 OTH exome

AF:

0.0000334

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152224

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74368

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:

0.0000882

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000793

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000117

AC:

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Inborn genetic diseases

Benign:1

Mar 07, 2025

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.38

BayesDel_addAF

Benign

-0.30

BayesDel_noAF

Benign

-0.47

CADD

Benign

DANN

Uncertain

0.97

DEOGEN2

Benign

0.023

Eigen

Benign

-0.11

Eigen_PC

Benign

-0.046

FATHMM_MKL

Uncertain

0.82

LIST_S2

Uncertain

0.89

M_CAP

Benign

0.062

MetaRNN

Benign

0.17

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.4

PrimateAI

Uncertain

0.75

PROVEAN

Benign

-2.2

REVEL

Benign

0.050

Sift

Benign

0.070

Sift4G

Benign

0.24

Polyphen

0.29

Vest4

0.33

MVP

0.43

MPC

0.69

ClinPred

0.11

GERP RS

4.5

Varity_R

0.090

gMVP

0.35

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