rs148631747

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_024753.5(TTC21B):​c.3350A>T​(p.Gln1117Leu) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,530 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q1117P) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TTC21B
NM_024753.5 missense

Scores

1
18

Clinical Significance

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

Conservation

PhyloP100: 4.78

Publications

0 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.16190279).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTC21BNM_024753.5 linkc.3350A>T p.Gln1117Leu missense_variant Exon 25 of 29 ENST00000243344.8 NP_079029.3
TTC21BXM_017004967.2 linkc.3350A>T p.Gln1117Leu missense_variant Exon 25 of 28 XP_016860456.1 A0A7P0TB61
TTC21BXM_047445870.1 linkc.2696A>T p.Gln899Leu missense_variant Exon 21 of 25 XP_047301826.1
TTC21BXM_011511871.4 linkc.2600A>T p.Gln867Leu missense_variant Exon 20 of 24 XP_011510173.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTC21BENST00000243344.8 linkc.3350A>T p.Gln1117Leu missense_variant Exon 25 of 29 1 NM_024753.5 ENSP00000243344.7 Q7Z4L5-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461530
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727096
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33468
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39626
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111790
Other (OTH)
AF:
0.00
AC:
0
AN:
60374
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Jeune thoracic dystrophy;C0687120:Nephronophthisis Uncertain:1
Aug 22, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. 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"). ClinVar contains an entry for this variant (Variation ID: 1012956). This variant has not been reported in the literature in individuals affected with TTC21B-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glutamine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 1117 of the TTC21B protein (p.Gln1117Leu). -

not provided Uncertain:1
Jan 01, 2021
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.099
BayesDel_addAF
Benign
-0.054
T
BayesDel_noAF
Benign
-0.32
CADD
Benign
18
DANN
Benign
0.88
DEOGEN2
Benign
0.12
T
Eigen
Benign
-0.26
Eigen_PC
Benign
-0.098
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Benign
0.38
T
M_CAP
Benign
0.020
T
MetaRNN
Benign
0.16
T
MetaSVM
Benign
-0.93
T
MutationAssessor
Benign
1.5
L
PhyloP100
4.8
PrimateAI
Benign
0.32
T
PROVEAN
Benign
-1.3
N
REVEL
Benign
0.15
Sift
Benign
0.29
T
Sift4G
Benign
0.31
T
Polyphen
0.0
B
Vest4
0.36
MutPred
0.42
Loss of disorder (P = 0.0627);
MVP
0.39
MPC
0.030
ClinPred
0.43
T
GERP RS
5.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.11
gMVP
0.38
Mutation Taster
=73/27
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

Other links and lift over

dbSNP: rs148631747; hg19: chr2-166744898; API