rs140757802

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_024753.5(TTC21B):​c.2014C>T​(p.Arg672Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000103 in 1,614,040 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/23 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R672P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000073 ( 0 hom. )

Consequence

TTC21B
NM_024753.5 missense

Scores

4
15

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2B:2

Conservation

PhyloP100: 1.83
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]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.14573875).
BP6
Variant 2-165915325-G-A is Benign according to our data. Variant chr2-165915325-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 261770.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTC21BNM_024753.5 linkc.2014C>T p.Arg672Trp missense_variant Exon 15 of 29 ENST00000243344.8 NP_079029.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTC21BENST00000243344.8 linkc.2014C>T p.Arg672Trp missense_variant Exon 15 of 29 1 NM_024753.5 ENSP00000243344.7 Q7Z4L5-1

Frequencies

GnomAD3 genomes
AF:
0.000388
AC:
59
AN:
152122
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00123
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000393
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000414
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000123
AC:
31
AN:
251370
AF XY:
0.000125
show subpopulations
Gnomad AFR exome
AF:
0.00117
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000732
AC:
107
AN:
1461800
Hom.:
0
Cov.:
32
AF XY:
0.0000825
AC XY:
60
AN XY:
727204
show subpopulations
Gnomad4 AFR exome
AF:
0.00146
AC:
49
AN:
33478
Gnomad4 AMR exome
AF:
0.000112
AC:
5
AN:
44724
Gnomad4 ASJ exome
AF:
0.00
AC:
0
AN:
26132
Gnomad4 EAS exome
AF:
0.00
AC:
0
AN:
39686
Gnomad4 SAS exome
AF:
0.000267
AC:
23
AN:
86256
Gnomad4 FIN exome
AF:
0.00
AC:
0
AN:
53418
Gnomad4 NFE exome
AF:
0.0000216
AC:
24
AN:
1111948
Gnomad4 Remaining exome
AF:
0.0000993
AC:
6
AN:
60394
Heterozygous variant carriers
0
7
14
21
28
35
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Exome Het
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.000394
AC:
60
AN:
152240
Hom.:
0
Cov.:
32
AF XY:
0.000336
AC XY:
25
AN XY:
74430
show subpopulations
Gnomad4 AFR
AF:
0.00125
AC:
0.00125175
AN:
0.00125175
Gnomad4 AMR
AF:
0.000393
AC:
0.000392722
AN:
0.000392722
Gnomad4 ASJ
AF:
0.00
AC:
0
AN:
0
Gnomad4 EAS
AF:
0.00
AC:
0
AN:
0
Gnomad4 SAS
AF:
0.000414
AC:
0.00041425
AN:
0.00041425
Gnomad4 FIN
AF:
0.00
AC:
0
AN:
0
Gnomad4 NFE
AF:
0.00
AC:
0
AN:
0
Gnomad4 OTH
AF:
0.00
AC:
0
AN:
0
Heterozygous variant carriers
0
4
7
11
14
18
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000204
Hom.:
0
Bravo
AF:
0.000525
ESP6500AA
AF:
0.00113
AC:
5
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000123
AC:
15

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Jeune thoracic dystrophy Pathogenic:1Uncertain:1
-
University of Washington Center for Mendelian Genomics, University of Washington
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

Jun 01, 2017
Dan Cohn Lab, University Of California Los Angeles
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:research

- -

not provided Uncertain:1
Aug 04, 2023
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Identified in individual with asphyxiating thoracic dystrophy; however, additional variants in other genes were also identified (Zhang et al., 2018); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 29068549) -

Jeune thoracic dystrophy;C0687120:Nephronophthisis Benign:1
Jan 12, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

TTC21B-related disorder Benign:1
Sep 23, 2024
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
Benign
0.13
BayesDel_addAF
Benign
-0.31
T
BayesDel_noAF
Benign
-0.25
CADD
Benign
18
DANN
Uncertain
1.0
DEOGEN2
Benign
0.36
T
Eigen
Benign
-0.22
Eigen_PC
Benign
-0.33
FATHMM_MKL
Benign
0.51
D
LIST_S2
Uncertain
0.91
D
M_CAP
Uncertain
0.097
D
MetaRNN
Benign
0.15
T
MetaSVM
Benign
-0.74
T
MutationAssessor
Benign
1.9
L
PrimateAI
Benign
0.36
T
PROVEAN
Benign
-1.4
N
REVEL
Benign
0.26
Sift
Benign
0.048
D
Sift4G
Uncertain
0.032
D
Polyphen
0.99
D
Vest4
0.56
MVP
0.47
MPC
0.089
ClinPred
0.016
T
GERP RS
2.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.070
gMVP
0.36
Mutation Taster
=90/10
polymorphism

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.

Other links and lift over

dbSNP: rs140757802; hg19: chr2-166771835; API