rs786200868

Positions:

• chr8-93755871-G-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2 PP3_Moderate PP5_Very_Strong

The NM_153704.6(TMEM67):​c.312+5G>A variant causes a splice donor 5th base, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000394 in 1,524,330 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.0000067 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000036 (0 hom.)
• Consequence: TMEM67 NM_153704.6 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 0.916

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 8-93755871-G-A is Pathogenic according to our data. Variant chr8-93755871-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 1380.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr8-93755871-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TMEM67	NM_153704.6	c.312+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000453321.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TMEM67	ENST00000453321.8	c.312+5G>A		splice_donor_5th_base_variant, intron_variant		1	NM_153704.6	P1

Frequencies

GnomAD3 genomes AF: 0.00000665 AC: 1 AN: 150350 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000245

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: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000364 AC: 5 AN: 1373980 Hom.: 0 Cov.: 22 AF XY: 0.00000583 AC XY: 4 AN XY: 686368

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000258

Gnomad4 SAS exome AF: 0.0000126

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000288

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000665 AC: 1 AN: 150350 Hom.: 0 Cov.: 31 AF XY: 0.0000137 AC XY: 1 AN XY: 73224

Gnomad4 AFR AF: 0.0000245

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Meckel-Gruber syndrome;C0431399:Familial aplasia of the vermis Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 31, 2022

For these reasons, this variant has been classified as Pathogenic. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exon 2 and introduces a premature termination codon (PMID: 27434533). The resulting mRNA is expected to undergo nonsense-mediated decay. ClinVar contains an entry for this variant (Variation ID: 1380). This variant has been observed in individual(s) with Joubert syndrome (PMID: 19058225, 27434533). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 2 of the TMEM67 gene. It does not directly change the encoded amino acid sequence of the TMEM67 protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or disrupted protein product. -

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

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Mar 24, 2022

- -

COACH syndrome 1 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Feb 01, 2009

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
CADD	Benign	15
DANN	Benign	0.34

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.77
SpliceAI score (max)		0.66		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.61		Position offset: 37
DS_DL_spliceai		0.66		Position offset: -5

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

Publications

LitVar

Other links and lift over

dbSNP: rs786200868; hg19: chr8-94768099; COSMIC: COSV60041662;