rs74447004

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_024753.5(TTC21B):c.724G>A(p.Asp242Asn) variant causes a missense change. The variant allele was found at a frequency of 0.00474 in 1,612,510 control chromosomes in the GnomAD database, including 32 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0036 ( 2 hom., cov: 32)

Exomes 𝑓: 0.0049 ( 30 hom. )

Consequence

TTC21B
NM_024753.5 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:11

Conservation

PhyloP100: 5.26

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:

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -20 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.005027771).

BP6

Variant 2-165933044-C-T is Benign according to our data. Variant chr2-165933044-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 130659.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-165933044-C-T is described in Lovd as [Benign].

BS1

Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00355 (541/152270) while in subpopulation NFE AF= 0.00569 (387/68022). AF 95% confidence interval is 0.00522. There are 2 homozygotes in gnomad4. There are 232 alleles in male gnomad4 subpopulation. This position pass quality control queck.

BS2

High Homozygotes in GnomAd at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTC21B	NM_024753.5 linkuse as main transcript	c.724G>A	p.Asp242Asn	missense_variant	7/29	ENST00000243344.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTC21B	ENST00000243344.8 linkuse as main transcript	c.724G>A	p.Asp242Asn	missense_variant	7/29	1	NM_024753.5	P1	Q7Z4L5-1

Frequencies

GnomAD3 genomes

AF:

0.00355

AC:

540

AN:

152152

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000893

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00242

Gnomad ASJ

AF:

0.0133

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00290

Gnomad FIN

AF:

0.000660

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.00570

Gnomad OTH

AF:

0.00479

GnomAD3 exomes

AF:

0.00415

AC:

1042

AN:

250952

Hom.:

AF XY:

0.00426

AC XY:

578

AN XY:

135630

show subpopulations

Gnomad AFR exome

AF:

0.00111

Gnomad AMR exome

AF:

0.00197

Gnomad ASJ exome

AF:

0.0143

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00160

Gnomad FIN exome

AF:

0.000882

Gnomad NFE exome

AF:

0.00628

Gnomad OTH exome

AF:

0.00506

GnomAD4 exome

AF:

0.00486

AC:

7104

AN:

1460240

Hom.:

Cov.:

AF XY:

0.00483

AC XY:

3510

AN XY:

726344

show subpopulations

Gnomad4 AFR exome

AF:

0.000807

Gnomad4 AMR exome

AF:

0.00235

Gnomad4 ASJ exome

AF:

0.0139

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00180

Gnomad4 FIN exome

AF:

0.00119

Gnomad4 NFE exome

AF:

0.00546

Gnomad4 OTH exome

AF:

0.00477

GnomAD4 genome

AF:

0.00355

AC:

541

AN:

152270

Hom.:

Cov.:

AF XY:

0.00312

AC XY:

232

AN XY:

74454

show subpopulations

Gnomad4 AFR

AF:

0.000938

Gnomad4 AMR

AF:

0.00242

Gnomad4 ASJ

AF:

0.0133

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00290

Gnomad4 FIN

AF:

0.000660

Gnomad4 NFE

AF:

0.00569

Gnomad4 OTH

AF:

0.00474

Alfa

AF:

0.00465

Hom.:

Bravo

AF:

0.00400

TwinsUK

AF:

0.00351

AC:

ALSPAC

AF:

0.00441

AC:

ESP6500AA

AF:

0.00159

AC:

ESP6500EA

AF:

0.00605

AC:

ExAC

AF:

0.00432

AC:

524

Asia WGS

AF:

0.00115

AC:

AN:

3476

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:11

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:5

Likely benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Jun 03, 2019	- -
Likely benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -
Benign, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Mar 05, 2019	- -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 15, 2018	- -
Benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -

not provided

Benign:3

Benign, criteria provided, single submitter	clinical testing	GeneDx	Nov 01, 2018	This variant is associated with the following publications: (PMID: 21258341, 26874042) -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Feb 01, 2023	TTC21B: BP4, BS2 -
Likely benign, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -

Asphyxiating thoracic dystrophy 4

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Jeune thoracic dystrophy;C0687120:Nephronophthisis

Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Jan 25, 2024

- -

Nephronophthisis 12

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Benign

-0.55

BayesDel_noAF

Benign

-0.56

Cadd

Uncertain

Dann

Uncertain

1.0

DEOGEN2

Benign

0.41

Eigen

Benign

0.063

Eigen_PC

Benign

0.22

FATHMM_MKL

Uncertain

0.95

LIST_S2

Benign

0.72

M_CAP

Benign

0.0093

MetaRNN

Benign

0.0050

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.7

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.49

PROVEAN

Uncertain

-3.1

REVEL

Benign

0.079

Sift

Benign

0.16

Sift4G

Benign

0.32

Polyphen

0.058

Vest4

0.36

MVP

0.30

MPC

0.036

ClinPred

0.025

GERP RS

4.2

Varity_R

0.19

gMVP

0.52

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