chr2-165919307-G-C

Variant summary

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

The NM_024753.5(TTC21B):​c.1643C>G​(p.Ser548Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000889 in 1,461,786 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

TTC21B
NM_024753.5 missense

Scores

1
7
11

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.96

Publications

1 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.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTC21BNM_024753.5 linkc.1643C>G p.Ser548Cys missense_variant Exon 13 of 29 ENST00000243344.8 NP_079029.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTC21BENST00000243344.8 linkc.1643C>G p.Ser548Cys missense_variant Exon 13 of 29 1 NM_024753.5 ENSP00000243344.7 Q7Z4L5-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000318
AC:
8
AN:
251284
AF XY:
0.0000221
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 FIN exome
AF:
0.0000924
Gnomad NFE exome
AF:
0.0000440
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.00000889
AC:
13
AN:
1461786
Hom.:
0
Cov.:
31
AF XY:
0.00000688
AC XY:
5
AN XY:
727198
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39678
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86240
European-Finnish (FIN)
AF:
0.000112
AC:
6
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111958
Other (OTH)
AF:
0.0000828
AC:
5
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.467
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
ExAC
AF:
0.0000494
AC:
6

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Jeune thoracic dystrophy;C0687120:Nephronophthisis Uncertain:1
Feb 03, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 548 of the TTC21B protein (p.Ser548Cys). This variant is present in population databases (rs777801181, gnomAD 0.01%). 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: 459286). 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: "Probably Damaging"; Align-GVGD: "Class C15"). 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
0.077
BayesDel_addAF
Uncertain
0.036
T
BayesDel_noAF
Uncertain
-0.060
CADD
Benign
23
DANN
Benign
0.93
DEOGEN2
Benign
0.10
T
Eigen
Uncertain
0.39
Eigen_PC
Uncertain
0.54
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.81
T
M_CAP
Benign
0.017
T
MetaRNN
Uncertain
0.50
T
MetaSVM
Benign
-0.99
T
MutationAssessor
Benign
1.7
L
PhyloP100
10
PrimateAI
Uncertain
0.68
T
PROVEAN
Benign
-0.16
N
REVEL
Uncertain
0.29
Sift
Benign
0.45
T
Sift4G
Benign
0.39
T
Polyphen
0.52
P
Vest4
0.77
MutPred
0.52
Gain of catalytic residue at L549 (P = 0.0112);
MVP
0.38
MPC
0.22
ClinPred
0.21
T
GERP RS
5.9
Varity_R
0.23
gMVP
0.32
Mutation Taster
=42/58
disease causing

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: rs777801181; hg19: chr2-166775817; API