chr2-165917286-T-C

Variant names:

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_024753.5(TTC21B):c.1870A>G(p.Ile624Val) variant causes a missense change. The variant allele was found at a frequency of 0.00113 in 1,614,190 control chromosomes in the GnomAD database, including 21 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.0056 ( 9 hom., cov: 32)

Exomes 𝑓: 0.00066 ( 12 hom. )

Consequence

TTC21B
NM_024753.5 missense

Scores

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:8

Conservation

PhyloP100: 4.88

Publications

5 publications found

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 Gene-Disease associations (from GenCC):

nephronophthisis 12
Inheritance: AD, AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae)
asphyxiating thoracic dystrophy 4
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
Jeune syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
nephronophthisis 2
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

TTC21B links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -20 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0028590262).

BP6

Variant 2-165917286-T-C is Benign according to our data. Variant chr2-165917286-T-C is described in ClinVar as [Benign]. Clinvar id is 331831.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.0056 (853/152332) while in subpopulation AFR AF = 0.0197 (818/41574). AF 95% confidence interval is 0.0186. There are 9 homozygotes in GnomAd4. There are 414 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High Homozygotes in GnomAd4 at 9 AR,AD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC21B	NM_024753.5 link	c.1870A>G	p.Ile624Val	missense_variant	Exon 14 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.1870A>G	p.Ile624Val	missense_variant	Exon 14 of 29	1	NM_024753.5	ENSP00000243344.7		Q7Z4L5-1

Frequencies

GnomAD3 genomes

AF:

0.00561

AC:

854

AN:

152214

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0198

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00137

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00382

GnomAD2 exomes

AF:

0.00157

AC:

395

AN:

251386

AF XY:

0.00126

show subpopulations

Gnomad AFR exome

AF:

0.0204

Gnomad AMR exome

AF:

0.00147

Gnomad ASJ exome

AF:

0.0000992

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.000978

GnomAD4 exome

AF:

0.000665

AC:

972

AN:

1461858

Hom.:

Cov.:

AF XY:

0.000575

AC XY:

418

AN XY:

727226

show subpopulations

African (AFR)

AF:

0.0230

AC:

771

AN:

33480

American (AMR)

AF:

0.00152

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.0000765

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39682

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00191

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000432

AC:

AN:

1112002

Other (OTH)

AF:

0.00116

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.483

Heterozygous variant carriers

114

170

227

284

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.00560

AC:

853

AN:

152332

Hom.:

Cov.:

AF XY:

0.00556

AC XY:

414

AN XY:

74494

show subpopulations

African (AFR)

AF:

0.0197

AC:

818

AN:

41574

American (AMR)

AF:

0.00137

AC:

AN:

15298

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.000207

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000735

AC:

AN:

68024

Other (OTH)

AF:

0.00378

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.502

Heterozygous variant carriers

120

160

200

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00252

Hom.:

Bravo

AF:

0.00651

ESP6500AA

AF:

0.0227

AC:

100

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.00180

AC:

219

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.000273

EpiControl

AF:

0.000119

ClinVar

Significance: Benign

Submissions summary: Benign:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:4

Genome Diagnostics Laboratory, University Medical Center Utrecht

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Nov 06, 2023

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 30, 2018

GeneDx

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 21258341) -

Breakthrough Genomics, Breakthrough Genomics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:not provided

- -

not specified

Benign:1

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jeune thoracic dystrophy;C0687120:Nephronophthisis

Benign:1

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Asphyxiating thoracic dystrophy 4

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory 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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Nephronophthisis 12

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.061

BayesDel_addAF

Benign

-0.55

BayesDel_noAF

Benign

-0.55

CADD

Benign

(source)

DANN

Benign

0.29

DEOGEN2

Benign

0.058

Eigen

Benign

-0.84

Eigen_PC

Benign

-0.57

FATHMM_MKL

Benign

0.29

LIST_S2

Benign

0.74

MetaRNN

Benign

0.0029

MetaSVM

Benign

-0.93

MutationAssessor

Benign

-1.8

PhyloP100

4.9

PrimateAI

Benign

0.26

PROVEAN

Benign

0.79

REVEL

Uncertain

0.29

Sift

Benign

1.0

Sift4G

Benign

1.0

Polyphen

0.0

Vest4

0.076

MVP

0.32

MPC

0.027

ClinPred

0.0045

GERP RS

4.9

Varity_R

0.037

gMVP

0.16

Mutation Taster

=93/7

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

chr2-165917286-T-C

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over