chr12-123690539-C-T

Variant summary

Our verdict is Benign. The variant received -19 ACMG points: 0P and 19B. BP4_ModerateBP6_Very_StrongBP7BS1BS2

The NM_024809.5(TCTN2):​c.898C>T​(p.Leu300Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0168 in 1,614,162 control chromosomes in the GnomAD database, including 319 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.011 ( 14 hom., cov: 32)
Exomes 𝑓: 0.017 ( 305 hom. )

Consequence

TCTN2
NM_024809.5 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:7

Conservation

PhyloP100: -0.0540

Publications

10 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: Benign. The variant received -19 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.39).
BP6
Variant 12-123690539-C-T is Benign according to our data. Variant chr12-123690539-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 126295.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-0.054 with no splicing effect.
BS1
Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.0111 (1688/152318) while in subpopulation SAS AF = 0.0306 (148/4830). AF 95% confidence interval is 0.0266. There are 14 homozygotes in GnomAd4. There are 833 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 14 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TCTN2NM_024809.5 linkc.898C>T p.Leu300Leu synonymous_variant Exon 8 of 18 ENST00000303372.7 NP_079085.2 Q96GX1-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TCTN2ENST00000303372.7 linkc.898C>T p.Leu300Leu synonymous_variant Exon 8 of 18 1 NM_024809.5 ENSP00000304941.5 Q96GX1-1

Frequencies

GnomAD3 genomes
AF:
0.0111
AC:
1685
AN:
152200
Hom.:
14
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00277
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00996
Gnomad ASJ
AF:
0.0153
Gnomad EAS
AF:
0.000385
Gnomad SAS
AF:
0.0302
Gnomad FIN
AF:
0.00669
Gnomad MID
AF:
0.0190
Gnomad NFE
AF:
0.0165
Gnomad OTH
AF:
0.00764
GnomAD2 exomes
AF:
0.0143
AC:
3601
AN:
251478
AF XY:
0.0163
show subpopulations
Gnomad AFR exome
AF:
0.00314
Gnomad AMR exome
AF:
0.00544
Gnomad ASJ exome
AF:
0.0156
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00813
Gnomad NFE exome
AF:
0.0158
Gnomad OTH exome
AF:
0.0137
GnomAD4 exome
AF:
0.0174
AC:
25398
AN:
1461844
Hom.:
305
Cov.:
32
AF XY:
0.0181
AC XY:
13181
AN XY:
727228
show subpopulations
African (AFR)
AF:
0.00254
AC:
85
AN:
33480
American (AMR)
AF:
0.00606
AC:
271
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.0158
AC:
412
AN:
26136
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39698
South Asian (SAS)
AF:
0.0389
AC:
3351
AN:
86252
European-Finnish (FIN)
AF:
0.00863
AC:
461
AN:
53416
Middle Eastern (MID)
AF:
0.0272
AC:
157
AN:
5768
European-Non Finnish (NFE)
AF:
0.0177
AC:
19709
AN:
1111976
Other (OTH)
AF:
0.0157
AC:
950
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.466
Heterozygous variant carriers
0
1415
2830
4244
5659
7074
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
776
1552
2328
3104
3880
<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:
0.0111
AC:
1688
AN:
152318
Hom.:
14
Cov.:
32
AF XY:
0.0112
AC XY:
833
AN XY:
74478
show subpopulations
African (AFR)
AF:
0.00279
AC:
116
AN:
41586
American (AMR)
AF:
0.00994
AC:
152
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.0153
AC:
53
AN:
3468
East Asian (EAS)
AF:
0.000386
AC:
2
AN:
5186
South Asian (SAS)
AF:
0.0306
AC:
148
AN:
4830
European-Finnish (FIN)
AF:
0.00669
AC:
71
AN:
10616
Middle Eastern (MID)
AF:
0.0204
AC:
6
AN:
294
European-Non Finnish (NFE)
AF:
0.0165
AC:
1124
AN:
68022
Other (OTH)
AF:
0.00756
AC:
16
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.495
Heterozygous variant carriers
0
92
184
276
368
460
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
26
52
78
104
130
<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:
0.0140
Hom.:
14
Bravo
AF:
0.00971
Asia WGS
AF:
0.0170
AC:
58
AN:
3478
EpiCase
AF:
0.0184
EpiControl
AF:
0.0168

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:3
Sep 06, 2016
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This 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. -

-
PreventionGenetics, part of Exact Sciences
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Genetic Services Laboratory, University of Chicago
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

Likely benign based on allele frequency in 1000 Genomes Project or ESP global frequency and its presence in a patient with a rare or unrelated disease phenotype. NOT Sanger confirmed. -

Joubert syndrome 24 Benign:1
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Meckel syndrome, type 8 Benign:1
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

not provided Benign:1
-
Breakthrough Genomics, Breakthrough Genomics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Meckel-Gruber syndrome;C0431399:Joubert syndrome Benign:1
Jan 30, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.39
CADD
Benign
7.2
DANN
Benign
0.64
PhyloP100
-0.054
Mutation Taster
=100/0
polymorphism (auto)

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: rs77804131; hg19: chr12-124175086; COSMIC: COSV57635066; COSMIC: COSV57635066; API