rs199821354

Variant names:

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 2P and 9B. PM2BP4_StrongBP6BS1

The NM_024753.5(TTC21B):c.511G>A(p.Gly171Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000198 in 1,613,470 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0012 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000095 ( 0 hom. )

Consequence

TTC21B
NM_024753.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:3

Conservation

PhyloP100: 3.43

Variant links:

Genes affected

TTC21B (HGNC:25660): (tetratricopeptide repeat domain 21B) This gene encodes a member of TTC21 family, containing several tetratricopeptide repeat (TPR) domains. This protein is localized to the cilium axoneme, and may play a role in retrograde intraflagellar transport in cilia. Mutations in this gene are associated with various ciliopathies, nephronophthisis 12, and asphyxiating thoracic dystrophy 4. [provided by RefSeq, Oct 2011]

TTC21B links:

TTC21B-AS1 (HGNC:41115): (TTC21B antisense RNA 1)

TTC21B-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -7 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.016461313).

BP6

Variant 2-165943260-C-T is Benign according to our data. Variant chr2-165943260-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 528908.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=2}.

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00118 (180/152254) while in subpopulation AFR AF= 0.00419 (174/41538). AF 95% confidence interval is 0.00368. There are 0 homozygotes in gnomad4. There are 93 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC21B	NM_024753.5 link	c.511G>A	p.Gly171Arg	missense_variant	Exon 5 of 29	ENST00000243344.8	NP_079029.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTC21B	ENST00000243344.8 link	c.511G>A	p.Gly171Arg	missense_variant	Exon 5 of 29	1	NM_024753.5	ENSP00000243344.7		Q7Z4L5-1

Frequencies

GnomAD3 genomes

AF:

0.00117

AC:

178

AN:

152136

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00415

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000393

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:

0.000239

AC:

AN:

251342

Hom.:

AF XY:

0.000206

AC XY:

AN XY:

135852

show subpopulations

Gnomad AFR exome

AF:

0.00345

Gnomad AMR exome

AF:

0.0000868

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000951

AC:

139

AN:

1461216

Hom.:

Cov.:

AF XY:

0.0000798

AC XY:

AN XY:

726956

show subpopulations

Gnomad4 AFR exome

AF:

0.00376

Gnomad4 AMR exome

AF:

0.000134

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:

0.00

Gnomad4 OTH exome

AF:

0.000116

GnomAD4 genome

AF:

0.00118

AC:

180

AN:

152254

Hom.:

Cov.:

AF XY:

0.00125

AC XY:

AN XY:

74450

show subpopulations

Gnomad4 AFR

AF:

0.00419

Gnomad4 AMR

AF:

0.000393

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:

0.000213

Hom.:

Bravo

AF:

0.00110

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000288

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1

Jul 24, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign in association with TTC21B-related ciliopathy to our knowledge; This variant is associated with the following publications: (PMID: 33100332) -

Breakthrough Genomics, Breakthrough Genomics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

Connective tissue disorder

Uncertain:1

Apr 22, 2022

Genome Diagnostics Laboratory, The Hospital for Sick Children

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jeune thoracic dystrophy;C0687120:Nephronophthisis

Benign:1

Jan 08, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

TTC21B-related disorder

Benign:1

Aug 16, 2021

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.38

BayesDel_addAF

Benign

-0.31

BayesDel_noAF

Benign

-0.22

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.46

Eigen

Benign

-0.067

Eigen_PC

Benign

-0.14

FATHMM_MKL

Uncertain

0.92

LIST_S2

Uncertain

0.90

M_CAP

Benign

0.052

MetaRNN

Benign

0.016

MetaSVM

Benign

-0.57

MutationAssessor

Uncertain

2.9

PrimateAI

Benign

0.47

PROVEAN

Pathogenic

-4.5

REVEL

Uncertain

0.29

Sift

Uncertain

0.0040

Sift4G

Benign

0.14

Polyphen

0.68

Vest4

0.71

MutPred

0.48

Loss of ubiquitination at K166 (P = 0.1264);

MVP

0.40

MPC

0.076

ClinPred

0.15

GERP RS

2.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.29

gMVP

0.79

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

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