rs16822802

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_024753.5(TTC21B):​c.1965G>A​(p.Arg655=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00141 in 1,613,976 control chromosomes in the GnomAD database, including 34 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0075 ( 16 hom., cov: 32)
Exomes 𝑓: 0.00078 ( 18 hom. )

Consequence

TTC21B
NM_024753.5 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:6

Conservation

PhyloP100: -0.287
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.71).
BP6
Variant 2-165915374-C-T is Benign according to our data. Variant chr2-165915374-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 379762.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-0.287 with no splicing effect.
BS1
Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00749 (1140/152154) while in subpopulation AFR AF= 0.0261 (1082/41510). AF 95% confidence interval is 0.0248. There are 16 homozygotes in gnomad4. There are 546 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
BS2
High Homozygotes in GnomAd4 at 16 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TTC21BNM_024753.5 linkuse as main transcriptc.1965G>A p.Arg655= synonymous_variant 15/29 ENST00000243344.8

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TTC21BENST00000243344.8 linkuse as main transcriptc.1965G>A p.Arg655= synonymous_variant 15/291 NM_024753.5 P1Q7Z4L5-1

Frequencies

GnomAD3 genomes
AF:
0.00750
AC:
1141
AN:
152036
Hom.:
16
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0262
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00269
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000415
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00718
GnomAD3 exomes
AF:
0.00195
AC:
491
AN:
251312
Hom.:
7
AF XY:
0.00154
AC XY:
209
AN XY:
135816
show subpopulations
Gnomad AFR exome
AF:
0.0273
Gnomad AMR exome
AF:
0.00110
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000229
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000489
GnomAD4 exome
AF:
0.000782
AC:
1143
AN:
1461822
Hom.:
18
Cov.:
32
AF XY:
0.000668
AC XY:
486
AN XY:
727212
show subpopulations
Gnomad4 AFR exome
AF:
0.0287
Gnomad4 AMR exome
AF:
0.00107
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.000174
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000234
Gnomad4 OTH exome
AF:
0.00149
GnomAD4 genome
AF:
0.00749
AC:
1140
AN:
152154
Hom.:
16
Cov.:
32
AF XY:
0.00734
AC XY:
546
AN XY:
74380
show subpopulations
Gnomad4 AFR
AF:
0.0261
Gnomad4 AMR
AF:
0.00268
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000416
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00711
Alfa
AF:
0.00352
Hom.:
7
Bravo
AF:
0.00835
Asia WGS
AF:
0.00202
AC:
7
AN:
3478
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:1
Benign, criteria provided, single submitterclinical testingGeneDxMay 10, 2016This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Asphyxiating thoracic dystrophy 4 Benign:1
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 12, 2018This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -
Jeune thoracic dystrophy;C0687120:Nephronophthisis Benign:1
Benign, criteria provided, single submitterclinical testingInvitaeJan 29, 2024- -
Nephronophthisis 12 Benign:1
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 12, 2018This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -
not provided Benign:1
Benign, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesNov 22, 2023- -
Connective tissue disorder Benign:1
Likely benign, criteria provided, single submitterclinical testingGenome Diagnostics Laboratory, The Hospital for Sick ChildrenJun 18, 2021- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.71
CADD
Benign
3.5
DANN
Benign
0.50
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs16822802; hg19: chr2-166771884; API