2-165919307-G-C

Variant names:

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

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

TTC21B links:

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
TTC21B	NM_024753.5 link	c.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
TTC21B	ENST00000243344.8 link	c.1643C>G	p.Ser548Cys	missense_variant	Exon 13 of 29	1	NM_024753.5	ENSP00000243344.7		Q7Z4L5-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000318

AC:

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:

AN:

1461786

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727198

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39678

South Asian (SAS)

AF:

0.00

AC:

AN:

86240

European-Finnish (FIN)

AF:

0.000112

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111958

Other (OTH)

AF:

0.0000828

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.467

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

ExAC

AF:

0.0000494

AC:

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

BayesDel_noAF

Uncertain

-0.060

CADD

Benign

(source)

DANN

Benign

0.93

DEOGEN2

Benign

0.10

Eigen

Uncertain

0.39

Eigen_PC

Uncertain

0.54

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.81

M_CAP

Benign

0.017

MetaRNN

Uncertain

0.50

MetaSVM

Benign

-0.99

MutationAssessor

Benign

1.7

PhyloP100

PrimateAI

Uncertain

0.68

PROVEAN

Benign

-0.16

REVEL

Uncertain

0.29

Sift

Benign

0.45

Sift4G

Benign

0.39

Polyphen

0.52

Vest4

0.77

MutPred

0.52

Gain of catalytic residue at L549 (P = 0.0112);

MVP

0.38

MPC

0.22

ClinPred

0.21

GERP RS

5.9

Varity_R

0.23

gMVP

0.32

Mutation Taster

=42/58

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over