Genetic Variant TTC21B:c.*544A>G (chr2-165874211-T-C) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_024753.5(TTC21B):c.*544A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000867 in 152,216 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 (★).

Frequency

Genomes: 𝑓 0.00087 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

TTC21B
NM_024753.5 3_prime_UTR

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:2

Conservation

PhyloP100: -1.56

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):

asphyxiating thoracic dystrophy 4
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
nephronophthisis 12
Inheritance: AR, AD Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
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: Likely_benign. The variant received -4 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.91).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024753.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTC21B	NM_024753.5	MANE Select	c.*544A>G		3_prime_UTR	Exon 29 of 29	NP_079029.3

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein	UniProt
TTC21B	ENST00000243344.8	TSL:1 MANE Select	c.*544A>G	3_prime_UTR	Exon 29 of 29	ENSP00000243344.7	Q7Z4L5-1
TTC21B	ENST00000959804.1		c.*544A>G	3_prime_UTR	Exon 28 of 28	ENSP00000629863.1
TTC21B	ENST00000679799.1		c.3806-3191A>G	intron	N/A	ENSP00000505208.1	A0A494C0N4

Frequencies

GnomAD3 genomes

AF:

0.000868

AC:

132

AN:

152098

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000459

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000916

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000945

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00141

Gnomad OTH

AF:

0.000479

GnomAD4 exome

Data not reliable, filtered out with message: AC0;AS_VQSR

AF:

0.00

AC:

AN:

330

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

232

African (AFR)

AF:

0.00

AC:

AN:

American (AMR)

AF:

0.00

AC:

AN:

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

East Asian (EAS)

AF:

0.00

AC:

AN:

South Asian (SAS)

AF:

0.00

AC:

AN:

European-Finnish (FIN)

AF:

0.00

AC:

AN:

Middle Eastern (MID)

AF:

0.00

AC:

AN:

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

282

Other (OTH)

AF:

0.00

AC:

AN:

GnomAD4 genome

AF:

0.000867

AC:

132

AN:

152216

Hom.:

Cov.:

AF XY:

0.000847

AC XY:

AN XY:

74422

show subpopulations

African (AFR)

AF:

0.000457

AC:

AN:

41552

American (AMR)

AF:

0.000915

AC:

AN:

15298

Ashkenazi Jewish (ASJ)

AF:

0.000288

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5160

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.0000945

AC:

AN:

10584

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00141

AC:

AN:

68010

Other (OTH)

AF:

0.000474

AC:

AN:

2108

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.501

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.000953

Hom.:

Bravo

AF:

0.000812

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

ClinVar submissions

Significance:Uncertain significance

Revision:criteria provided, single submitter

View on ClinVar

Pathogenic

VUS

Benign

Condition

Asphyxiating thoracic dystrophy 4 (1)

Nephronophthisis 12 (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.91

CADD

Benign

1.6

(source)

DANN

Benign

0.54

PhyloP100

-1.6

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over