Genetic Variant TTC21B:p.Ala91Gly (chr2-165945681-G-C) – ACMG Classification: Uncertain_significance (1 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP4

The NM_024753.5(TTC21B):c.272C>G(p.Ala91Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,612,970 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. A91D) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

TTC21B
NM_024753.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.68

Publications

5 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 links:

TTC21B-AS1 (HGNC:41115): (TTC21B antisense RNA 1)

TTC21B-AS1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.28760135).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC21B	NM_024753.5 link	c.272C>G	p.Ala91Gly	missense_variant	Exon 4 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.272C>G	p.Ala91Gly	missense_variant	Exon 4 of 29	1	NM_024753.5	ENSP00000243344.7

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152108

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.00316

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1460744

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

726690

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33458

American (AMR)

AF:

0.00

AC:

AN:

44710

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26120

East Asian (EAS)

AF:

0.00

AC:

AN:

39610

South Asian (SAS)

AF:

0.00

AC:

AN:

86170

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52916

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111626

Other (OTH)

AF:

0.0000331

AC:

AN:

60370

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.00000657

AC:

AN:

152226

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74446

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41532

American (AMR)

AF:

0.00

AC:

AN:

15294

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10592

Middle Eastern (MID)

AF:

0.00340

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68024

Other (OTH)

AF:

0.00

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Asphyxiating thoracic dystrophy 4;C3151186:Nephronophthisis 12

Uncertain:1

Jun 17, 2024

Fulgent Genetics, Fulgent Genetics

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

0.19

BayesDel_addAF

Benign

-0.067

BayesDel_noAF

Benign

-0.33

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.42

Eigen

Uncertain

0.50

Eigen_PC

Uncertain

0.54

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.87

M_CAP

Benign

0.023

MetaRNN

Benign

0.29

MetaSVM

Benign

-0.63

MutationAssessor

Uncertain

2.5

PhyloP100

4.7

PrimateAI

Benign

0.37

PROVEAN

Uncertain

-3.3

REVEL

Benign

0.19

Sift

Uncertain

0.0050

Sift4G

Uncertain

0.0080

Polyphen

0.61

Vest4

0.46

MutPred

0.44

Gain of disorder (P = 0.1392);

MVP

0.38

MPC

0.094

ClinPred

0.98

GERP RS

5.5

Varity_R

0.27

gMVP

0.22

Mutation Taster

=70/30

polymorphism

(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

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over