NM_153704.6:c.651+2T>G

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PVS1_ModeratePM2PP5

The NM_153704.6(TMEM67):​c.651+2T>G variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.0000729 in 1,605,100 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000076 ( 0 hom. )

Consequence

TMEM67
NM_153704.6 splice_donor, intron

Scores

4
2
1
Splicing: ADA: 1.000
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:9U:1

Conservation

PhyloP100: 4.87

Publications

3 publications found
Variant links:
Genes affected
TMEM67 (HGNC:28396): (transmembrane protein 67) The protein encoded by this gene localizes to the primary cilium and to the plasma membrane. The gene functions in centriole migration to the apical membrane and formation of the primary cilium. Multiple transcript variants encoding different isoforms have been found for this gene. Defects in this gene are a cause of Meckel syndrome type 3 (MKS3) and Joubert syndrome type 6 (JBTS6). [provided by RefSeq, Nov 2008]
TMEM67 Gene-Disease associations (from GenCC):
  • ciliopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • COACH syndrome 1
    Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
  • Meckel syndrome, type 3
    Inheritance: AR Classification: DEFINITIVE Submitted by: Ambry Genetics
  • nephronophthisis 11
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
  • COACH syndrome 1
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics
  • Joubert syndrome 6
    Inheritance: AR Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • Joubert syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Meckel syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Senior-Boichis syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.025100403 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.8, offset of 4, new splice context is: ggaGTatgt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 8-93765648-T-G is Pathogenic according to our data. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373. Variant chr8-93765648-T-G is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 1373.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TMEM67NM_153704.6 linkc.651+2T>G splice_donor_variant, intron_variant Intron 6 of 27 ENST00000453321.8 NP_714915.3 Q5HYA8

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TMEM67ENST00000453321.8 linkc.651+2T>G splice_donor_variant, intron_variant Intron 6 of 27 1 NM_153704.6 ENSP00000389998.3 Q5HYA8

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152246
Hom.:
0
Cov.:
32
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:
0.0000941
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000557
AC:
14
AN:
251174
AF XY:
0.0000515
show subpopulations
Gnomad AFR exome
AF:
0.0000620
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.000106
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000764
AC:
111
AN:
1452736
Hom.:
0
Cov.:
28
AF XY:
0.0000705
AC XY:
51
AN XY:
723506
show subpopulations
African (AFR)
AF:
0.0000901
AC:
3
AN:
33290
American (AMR)
AF:
0.00
AC:
0
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26092
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39620
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86062
European-Finnish (FIN)
AF:
0.0000562
AC:
3
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5744
European-Non Finnish (NFE)
AF:
0.0000933
AC:
103
AN:
1103718
Other (OTH)
AF:
0.0000333
AC:
2
AN:
60086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.460
Heterozygous variant carriers
0
4
9
13
18
22
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000394
AC:
6
AN:
152364
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74518
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41586
American (AMR)
AF:
0.00
AC:
0
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.0000941
AC:
1
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.0000605
Hom.:
0
Bravo
AF:
0.0000340
ExAC
AF:
0.0000494
AC:
6
EpiCase
AF:
0.000164
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:9Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:4
Oct 02, 2021
Revvity Omics, Revvity
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Clinical Genetics, Academic Medical Center
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

May 29, 2024
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Canonical splice site variant predicted to result in an in-frame loss of the adjacent exon in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25525159, 31589614, 16541367, 17160906, 17397051, 19466712, 36090483) -

Meckel syndrome, type 3 Pathogenic:1Uncertain:1
Apr 21, 2017
Institute of Human Genetics, University of Leipzig Medical Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Joubert syndrome and related disorders Pathogenic:1
Jul 18, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TMEM67 c.651+2T>G is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: three predict the variant abolishes the canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 5.6e-05 in 251174 control chromosomes (gnomAD). This frequency is not higher than the estimated maximum expected for a pathogenic variant in TMEM67 causing Joubert Syndrome and Related Disorders (0.0018), allowing no conclusion about variant significance. c.651+2T>G has been reported in the literature in individuals affected with Joubert Syndrome and Meckel syndrome (Baala_2007 and Khaddour_2007). Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as VUS (n=1), likely pathogenic (n=1) and pathogenic (n=1). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Joubert syndrome 6 Pathogenic:1
Jan 01, 2007
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Meckel-Gruber syndrome;C0431399:Joubert syndrome Pathogenic:1
Jun 25, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change affects a donor splice site in intron 6 of the TMEM67 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in TMEM67 are known to be pathogenic (PMID: 20232449, 23559409). This variant is present in population databases (rs199821258, gnomAD 0.01%). Disruption of this splice site has been observed in individual(s) with Joubert syndrome (PMID: 17160906). ClinVar contains an entry for this variant (Variation ID: 1373). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

TMEM67-related disorder Pathogenic:1
Sep 25, 2024
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The TMEM67 c.651+2T>G variant is predicted to disrupt the GT donor site and interfere with normal splicing. This variant has been reported in individuals with Joubert syndrome and Meckel-Gruber syndrome (Baala et al. 2007. PubMed ID: 17160906; Khaddour et al. 2007. PubMed ID: 17397051). This variant is reported in 0.011% of alleles in individuals of European (Non-Finnish) descent in gnomAD. Variants that disrupt the consensus splice donor site in TMEM67 are expected to be pathogenic. Given the evidence, we interpret this variant as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.48
D
BayesDel_noAF
Pathogenic
0.23
CADD
Pathogenic
31
DANN
Uncertain
0.99
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.85
FATHMM_MKL
Uncertain
0.95
D
PhyloP100
4.9
GERP RS
5.7
Mutation Taster
=0/100
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.95
SpliceAI score (max)
0.76
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.76
Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs199821258; hg19: chr8-94777876; API