rs386834192
Variant summary
Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2PP3_ModeratePP5
The NM_153704.6(TMEM67):c.2322+2dupT variant causes a splice region, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000335 in 1,520,812 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_153704.6 splice_region, intron
Scores
Clinical Significance
Conservation
Publications
- ciliopathyInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
 - COACH syndrome 1Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
 - Meckel syndrome, type 3Inheritance: AR Classification: DEFINITIVE Submitted by: Ambry Genetics
 - nephronophthisis 11Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
 - COACH syndrome 1Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics
 - Joubert syndrome 6Inheritance: AR Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
 - Joubert syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
 - Meckel syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
 - Senior-Boichis syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
 
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ACMG classification
Our verdict: Uncertain_significance. The variant received 5 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes   AF:  0.0000131  AC: 2AN: 152126Hom.:  0  Cov.: 32 show subpopulations 
GnomAD2 exomes  AF:  0.0000279  AC: 7AN: 251108 AF XY:  0.0000147   show subpopulations 
GnomAD4 exome  AF:  0.0000358  AC: 49AN: 1368686Hom.:  0  Cov.: 22 AF XY:  0.0000321  AC XY: 22AN XY: 686146 show subpopulations 
Age Distribution
GnomAD4 genome   AF:  0.0000131  AC: 2AN: 152126Hom.:  0  Cov.: 32 AF XY:  0.00  AC XY: 0AN XY: 74328 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
Joubert syndrome 6    Pathogenic:2 
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A heterozygous canonical splice site variant, NM_153704.5(TMEM67):c.2322+2dupT, has been identified in intron 22 of 27 of the TMEM67 gene. The conservation of this nucleotide was very high (UCSC, Phylop), and in silico tools consistently predict this variant to affect splicing (Human splicing Finder, Fruit fly, Netgene2). This duplication variant may result in a truncated protein; further testing via RNA studies are required to confirm if splicing is altered. The variant is present in the gnomAD database at a frequency of 0.00283% (8 heterozygotes, 0 homozygotes). The variant has been previously described as both a VUS and pathogenic in patients with Joubert syndrome (ClinVar). Subsequent analysis of parental samples indicated this variant was paternally inherited. Based on current information, this variant has been classified as PATHOGENIC. NB: This variant has been reclassified as PATHOGENIC due to confirmation of a pathogenic variant in trans. -
Meckel syndrome, type 3    Pathogenic:1 
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Meckel syndrome, type 3;C1853153:Joubert syndrome 6;C1865794:RHYNS syndrome;C2673874:Bardet-Biedl syndrome 14;C3150796:Nephronophthisis 11;C5435651:COACH syndrome 1    Pathogenic:1 
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COACH syndrome 1    Pathogenic:1 
This sequence variant is a single nucleotide duplication (dupT) at the +2 position of the intron 22 canonical splice donor site of the TMEM67 gene. This variant is predicted to generate a non-functiol allele through either the expression of a truncated protein or a loss of TMEM67 expression due to nonsense mediated decay. This is a previously reported variant (ClinVar 56773). Aside from literature reports on the proband (PMID: 19574260, 28125082), this variant has additiolly been observed in trans with a second TMEM67 variant in multiple individuals affected by Joubert syndrome, Meckel syndrome, or other TMEM67-related disorders (PMID: 28497568, 26092869, 20232449); in one individual with suspected monogenic kidney disease, it was unclear if a second TMEM67 variant was present (PMID: 32939031). This variant is present in 8 of 282484 alleles (0.0028%) in the gnomAD population dataset. In a lymphoblastoid cell line derived from the proband which presumably carried the variant, splicing of exon 22 was not affected (PMID: 19574260). Based upon the evidence, we consider this variant to be likely pathogenic. ACMG Criteria: PM2, PS4, PVS1 -
Meckel-Gruber syndrome;C0431399:Joubert syndrome    Pathogenic:1 
This sequence change falls in intron 22 of the TMEM67 gene. It does not directly change the encoded amino acid sequence of the TMEM67 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs781071815, gnomAD 0.006%). This variant has been observed in individual(s) with Joubert syndrome and related disorders (PMID: 20232449, 26092869, 28497568). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is also known as c.2322+2dupT. ClinVar contains an entry for this variant (Variation ID: 56773). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). 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. -
not provided    Uncertain:1 
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Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at