Genetic Variant TBC1D21:p.Phe251Phe (chr15-73886588-C-T) – ACMG Classification: Likely_benign (-5 pts)

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 2P and 7B. PM2BP4_StrongBP6_ModerateBP7

The NM_153356.3(TBC1D21):c.753C>T(p.Phe251Phe) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000753 in 1,461,248 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 Likely benign (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

TBC1D21
NM_153356.3 synonymous

Scores

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: -2.39

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:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.47).

BP6

Variant 15-73886588-C-T is Benign according to our data. Variant chr15-73886588-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 3804591.Status of the report is criteria_provided_single_submitter, 1 stars.

BP7

Synonymous conserved (PhyloP=-2.39 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TBC1D21	NM_153356.3 link	c.753C>T	p.Phe251Phe	synonymous_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.753C>T	p.Phe251Phe	synonymous_variant	Exon 8 of 11	1	NM_153356.3	ENSP00000300504.2	Q8IYX1-1
TBC1D21	ENST00000535547.6 link	c.645C>T	p.Phe215Phe	synonymous_variant	Exon 7 of 10	1		ENSP00000439325.2	Q8IYX1-2
TBC1D21	ENST00000562056.1 link	c.642C>T	p.Phe214Phe	synonymous_variant	Exon 7 of 10	5		ENSP00000457096.1	H3BTA9

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251404

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135866

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:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000753

AC:

AN:

1461248

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

726924

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000719

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

Cov.:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Benign:1

Mar 04, 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

BayesDel_noAF

Benign

-0.47

CADD

Benign

2.8

DANN

Benign

0.77

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