2-165888388-T-G

Position:

chr2-165888388-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_024753.5(TTC21B):c.3350A>C(p.Gln1117Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000496 in 1,613,738 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

TTC21B
NM_024753.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 4.78

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 Uncertain_significance. Variant got 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.23657653).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
TTC21B	NM_024753.5 linkuse as main transcript	c.3350A>C	p.Gln1117Pro	missense_variant	25/29	ENST00000243344.8	NP_079029.3
TTC21B	XM_017004967.2 linkuse as main transcript	c.3350A>C	p.Gln1117Pro	missense_variant	25/28		XP_016860456.1
TTC21B	XM_047445870.1 linkuse as main transcript	c.2696A>C	p.Gln899Pro	missense_variant	21/25		XP_047301826.1
TTC21B	XM_011511871.4 linkuse as main transcript	c.2600A>C	p.Gln867Pro	missense_variant	20/24		XP_011510173.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTC21B	ENST00000243344.8 linkuse as main transcript	c.3350A>C	p.Gln1117Pro	missense_variant	25/29	1	NM_024753.5	ENSP00000243344	P1	Q7Z4L5-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152208

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251246

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135814

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:

0.00000411

AC:

AN:

1461530

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727096

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

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:

0.00000450

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74364

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000987

Hom.:

Bravo

AF:

0.0000264

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Asphyxiating thoracic dystrophy 4;C3151186:Nephronophthisis 12

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Aug 13, 2021

- -

Jeune thoracic dystrophy;C0687120:Nephronophthisis

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 19, 2022

This sequence change replaces glutamine, which is neutral and polar, with proline, which is neutral and non-polar, at codon 1117 of the TTC21B protein (p.Gln1117Pro). This variant is present in population databases (rs148631747, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with TTC21B-related conditions. ClinVar contains an entry for this variant (Variation ID: 572325). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.070

BayesDel_addAF

Benign

-0.029

BayesDel_noAF

Benign

-0.28

CADD

Benign

DANN

Benign

0.63

DEOGEN2

Benign

0.043

Eigen

Benign

-0.31

Eigen_PC

Benign

-0.14

FATHMM_MKL

Uncertain

0.96

LIST_S2

Benign

0.59

M_CAP

Benign

0.016

MetaRNN

Benign

0.24

MetaSVM

Benign

-0.97

MutationAssessor

Benign

1.5

MutationTaster

Benign

0.98

D;D

PrimateAI

Benign

0.33

PROVEAN

Benign

0.25

REVEL

Benign

0.19

Sift

Benign

0.28

Sift4G

Benign

0.28

Polyphen

0.0

Vest4

0.49

MVP

0.31

MPC

0.034

ClinPred

0.21

GERP RS

5.8

Varity_R

0.13

gMVP

0.60

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