rs201827132

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PM5PP3PP5

The NM_024809.5(TCTN2):​c.613G>A​(p.Gly205Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000867 in 1,613,994 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G205C) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

TCTN2
NM_024809.5 missense

Scores

4
11
4

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1

Conservation

PhyloP100: 6.64

Publications

4 publications found
Variant links:
Genes affected
TCTN2 (HGNC:25774): (tectonic family member 2) This gene encodes a type I membrane protein that belongs to the tectonic family. Studies in mice suggest that this protein may be involved in hedgehog signaling, and essential for ciliogenesis. Mutations in this gene are associated with Meckel syndrome type 8. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2011]
TCTN2 Gene-Disease associations (from GenCC):
  • Joubert syndrome 24
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: ClinGen, G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • Joubert syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Meckel syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr12-123686884-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 217702.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.828
PP5
Variant 12-123686884-G-A is Pathogenic according to our data. Variant chr12-123686884-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1975729.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TCTN2NM_024809.5 linkc.613G>A p.Gly205Ser missense_variant Exon 6 of 18 ENST00000303372.7 NP_079085.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TCTN2ENST00000303372.7 linkc.613G>A p.Gly205Ser missense_variant Exon 6 of 18 1 NM_024809.5 ENSP00000304941.5

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152100
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000656
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251492
AF XY:
0.0000147
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:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000752
AC:
11
AN:
1461894
Hom.:
0
Cov.:
33
AF XY:
0.00000825
AC XY:
6
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000989
AC:
11
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.498
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000197
AC:
3
AN:
152100
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74298
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41412
American (AMR)
AF:
0.0000656
AC:
1
AN:
15252
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.00
Hom.:
0
Bravo
AF:
0.00000756
EpiCase
AF:
0.00
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Meckel-Gruber syndrome;C0431399:Joubert syndrome Pathogenic:1
Mar 12, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Gly205 amino acid residue in TCTN2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 26092869). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TCTN2 protein function. This variant has not been reported in the literature in individuals affected with TCTN2-related conditions. This variant is present in population databases (rs201827132, gnomAD 0.002%). This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 205 of the TCTN2 protein (p.Gly205Ser). -

Meckel syndrome, type 8;C4084841:Joubert syndrome 24 Uncertain:1
Jan 30, 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
0.15
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Uncertain
0.070
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.52
.;D
Eigen
Uncertain
0.34
Eigen_PC
Uncertain
0.27
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.78
T;T
M_CAP
Uncertain
0.11
D
MetaRNN
Pathogenic
0.83
D;D
MetaSVM
Uncertain
0.097
D
MutationAssessor
Uncertain
2.5
.;M
PhyloP100
6.6
PrimateAI
Uncertain
0.61
T
PROVEAN
Uncertain
-3.5
D;D
REVEL
Uncertain
0.55
Sift
Benign
0.059
T;T
Sift4G
Pathogenic
0.0
D;D
Polyphen
0.99
.;D
Vest4
0.58
MutPred
0.71
.;Gain of catalytic residue at S201 (P = 2e-04);
MVP
0.90
MPC
0.48
ClinPred
0.95
D
GERP RS
5.7
Varity_R
0.33
gMVP
0.70
Mutation Taster
=41/59
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: rs201827132; hg19: chr12-124171431; API