Genetic Variant TBC1D21:p.Arg246Cys (chr15-73886571-C-T) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3

The NM_153356.3(TBC1D21):c.736C>T(p.Arg246Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000279 in 1,613,616 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R246S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

TBC1D21
NM_153356.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.22

Variant links:

Genes affected

TBC1D21 (HGNC:28536): (TBC1 domain family member 21) Predicted to enable GTPase activator activity. Predicted to be involved in activation of GTPase activity and intracellular protein transport. Located in extracellular exosome. [provided by Alliance of Genome Resources, Apr 2022]

TBC1D21 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.793

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TBC1D21	NM_153356.3 link	c.736C>T	p.Arg246Cys	missense_variant	Exon 8 of 11	ENST00000300504.7	NP_699187.1	Q8IYX1-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
TBC1D21	ENST00000300504.7 link	c.736C>T	p.Arg246Cys	missense_variant	Exon 8 of 11	1	NM_153356.3	ENSP00000300504.2	Q8IYX1-1
TBC1D21	ENST00000535547.6 link	c.628C>T	p.Arg210Cys	missense_variant	Exon 7 of 10	1		ENSP00000439325.2	Q8IYX1-2
TBC1D21	ENST00000562056.1 link	c.625C>T	p.Arg209Cys	missense_variant	Exon 7 of 10	5		ENSP00000457096.1	H3BTA9

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152228

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000358

AC:

AN:

251420

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135882

show subpopulations

Gnomad AFR exome

AF:

0.000123

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:

0.0000616

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000294

AC:

AN:

1461388

Hom.:

Cov.:

AF XY:

0.0000234

AC XY:

AN XY:

726988

show subpopulations

Gnomad4 AFR exome

AF:

0.000120

Gnomad4 AMR exome

AF:

0.00

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:

0.0000324

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152228

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74366

show subpopulations

Gnomad4 AFR

AF:

0.0000482

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000565

Hom.:

Bravo

AF:

0.0000264

ExAC

AF:

0.0000247

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Dec 10, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.736C>T (p.R246C) alteration is located in exon 8 (coding exon 8) of the TBC1D21 gene. This alteration results from a C to T substitution at nucleotide position 736, causing the arginine (R) at amino acid position 246 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Benign

-0.24

BayesDel_noAF

Benign

-0.35

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.40

.;T;T

Eigen

Benign

0.13

Eigen_PC

Benign

0.079

FATHMM_MKL

Benign

0.12

LIST_S2

Uncertain

0.92

D;D;D

M_CAP

Benign

0.020

MetaRNN

Pathogenic

0.79

D;D;D

MetaSVM

Benign

-1.0

MutationAssessor

Benign

1.9

.;L;.

PrimateAI

Benign

0.43

PROVEAN

Pathogenic

-7.5

D;D;D

REVEL

Benign

0.18

Sift

Pathogenic

0.0

D;D;D

Sift4G

Uncertain

0.0060

D;D;D

Polyphen

0.98

.;D;.

Vest4

0.67

MutPred

0.74

.;Loss of MoRF binding (P = 0.0349);.;

MVP

0.58

MPC

0.95

ClinPred

0.84

GERP RS

3.0

Varity_R

0.64

gMVP

0.82

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.060

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