rs185089786

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_024753.5(TTC21B):​c.1231C>T​(p.Arg411*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,611,936 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000028 ( 0 hom. )

Consequence

TTC21B
NM_024753.5 stop_gained

Scores

2
2
3

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 0.521

Publications

9 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: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 2-165929290-G-A is Pathogenic according to our data. Variant chr2-165929290-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 30938.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTC21BNM_024753.5 linkc.1231C>T p.Arg411* stop_gained Exon 11 of 29 ENST00000243344.8 NP_079029.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTC21BENST00000243344.8 linkc.1231C>T p.Arg411* stop_gained Exon 11 of 29 1 NM_024753.5 ENSP00000243344.7

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152010
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000966
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
250066
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000582
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000885
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000281
AC:
41
AN:
1459926
Hom.:
0
Cov.:
31
AF XY:
0.0000220
AC XY:
16
AN XY:
726324
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33412
American (AMR)
AF:
0.0000898
AC:
4
AN:
44568
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26092
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39566
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86152
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53354
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5666
European-Non Finnish (NFE)
AF:
0.0000315
AC:
35
AN:
1110818
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60298
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.414
Heterozygous variant carriers
0
3
7
10
14
17
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

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:
0.0000329
AC:
5
AN:
152010
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74242
show subpopulations
African (AFR)
AF:
0.0000966
AC:
4
AN:
41416
American (AMR)
AF:
0.00
AC:
0
AN:
15246
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67920
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.445
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

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:
0.00
Hom.:
0
Bravo
AF:
0.0000264
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Jeune thoracic dystrophy;C0687120:Nephronophthisis Pathogenic:1
Oct 30, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg411*) in the TTC21B gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in TTC21B are known to be pathogenic (PMID: 18327258, 21068128, 21258341, 23559409, 24876116, 25492405, 27491411, 29068549). This variant is present in population databases (rs185089786, gnomAD 0.009%). This premature translational stop signal has been observed in individual(s) with Jeune asphyxiating thoracic dystrophy (PMID: 21258341). ClinVar contains an entry for this variant (Variation ID: 30938). For these reasons, this variant has been classified as Pathogenic. -

Asphyxiating thoracic dystrophy 4 Pathogenic:1
Mar 01, 2011
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

not provided Pathogenic:1
Jan 04, 2022
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25525159, 21258341) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.49
D
BayesDel_noAF
Pathogenic
0.29
CADD
Pathogenic
35
DANN
Uncertain
1.0
Eigen
Uncertain
0.19
Eigen_PC
Benign
-0.12
FATHMM_MKL
Benign
0.13
N
PhyloP100
0.52
Vest4
0.20
GERP RS
-0.10
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Mutation Taster
=9/191
disease causing (ClinVar)

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: rs185089786; hg19: chr2-166785800; API