rs146637219

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 2P and 16B. PM2BP4_StrongBP6_Very_StrongBS1

The NM_024753.5(TTC21B):c.2161A>C(p.Asn721His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000218 in 1,613,014 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0012 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00012 ( 1 hom. )

Consequence

TTC21B
NM_024753.5 missense

Scores

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts U:1B:3

Conservation

PhyloP100: 2.64

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -14 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.0096232).

BP6

Variant 2-165913624-T-G is Benign according to our data. Variant chr2-165913624-T-G is described in ClinVar as [Likely_benign]. Clinvar id is 261772.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 = 0.00116 (176/152274) while in subpopulation AFR AF= 0.00399 (166/41564). AF 95% confidence interval is 0.0035. There are 0 homozygotes in gnomad4. There are 80 alleles in male gnomad4 subpopulation. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTC21B	NM_024753.5 linkuse as main transcript	c.2161A>C	p.Asn721His	missense_variant	16/29	ENST00000243344.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTC21B	ENST00000243344.8 linkuse as main transcript	c.2161A>C	p.Asn721His	missense_variant	16/29	1	NM_024753.5	P1	Q7Z4L5-1

Frequencies

GnomAD3 genomes

AF:

0.00116

AC:

177

AN:

152156

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00403

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000524

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:

0.000955

GnomAD3 exomes

AF:

0.000343

AC:

AN:

250766

Hom.:

AF XY:

0.000170

AC XY:

AN XY:

135634

show subpopulations

Gnomad AFR exome

AF:

0.00482

Gnomad AMR exome

AF:

0.000203

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:

0.00000882

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000120

AC:

175

AN:

1460740

Hom.:

Cov.:

AF XY:

0.0000826

AC XY:

AN XY:

726780

show subpopulations

Gnomad4 AFR exome

AF:

0.00454

Gnomad4 AMR exome

AF:

0.000179

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:

0.00000180

Gnomad4 OTH exome

AF:

0.000215

GnomAD4 genome

AF:

0.00116

AC:

176

AN:

152274

Hom.:

Cov.:

AF XY:

0.00107

AC XY:

AN XY:

74464

show subpopulations

Gnomad4 AFR

AF:

0.00399

Gnomad4 AMR

AF:

0.000523

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:

0.000945

Alfa

AF:

0.000240

Hom.:

Bravo

AF:

0.00145

ESP6500AA

AF:

0.00409

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000428

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Likely benign

Submissions summary: Uncertain:1Benign:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1Benign:1

Uncertain significance, no assertion criteria provided	clinical testing	Genetic Services Laboratory, University of Chicago	Aug 26, 2022	DNA sequence analysis of the TTC21B gene demonstrated a sequence change, c.2161A>C, in exon 16 that results in an amino acid change, p.Asn721His. This sequence change does not appear to have been previously described in individuals with TTC21B-related. This sequence change has been described in the gnomAD database with a frequency of 0.44% in the African subpopulation and 0.042% in the overall population (dbSNP rs146637219). The p.Asn721His change affects a poorly conserved amino acid residue located in a domain of the TTC21B protein that is known to be functional. In-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL) provide contradictory results for the p.Asn721His substitution. Due to insufficient evidences and the lack of functional studies, the clinical significance of the p.Asn721His change remains unknown at this time. -
Likely benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -

Jeune thoracic dystrophy;C0687120:Nephronophthisis

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jan 17, 2024

- -

not provided

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Apr 08, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.093

BayesDel_addAF

Benign

-0.55

BayesDel_noAF

Benign

-0.56

Cadd

Benign

Dann

Benign

0.92

DEOGEN2

Benign

0.40

Eigen

Benign

-0.085

Eigen_PC

Benign

-0.19

FATHMM_MKL

Uncertain

0.94

LIST_S2

Benign

0.74

M_CAP

Benign

0.017

MetaRNN

Benign

0.0096

MetaSVM

Benign

-0.79

MutationAssessor

Uncertain

2.0

MutationTaster

Benign

0.94

PrimateAI

Benign

0.33

PROVEAN

Benign

-1.9

REVEL

Benign

0.21

Sift

Benign

0.058

Sift4G

Benign

0.18

Polyphen

0.84

Vest4

0.21

MVP

0.40

MPC

0.12

ClinPred

0.062

GERP RS

1.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.064

gMVP

0.32

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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