rs786200867

Positions:

• chr8-93808957-G-A
• chr8-93808957-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_153704.6(TMEM67):​c.2556+1G>A variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TMEM67 NM_153704.6 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.70

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 Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.038821954 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-93808957-G-A is Pathogenic according to our data. Variant chr8-93808957-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 2925441.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TMEM67	NM_153704.6	c.2556+1G>A		splice_donor_variant		ENST00000453321.8	NP_714915.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TMEM67	ENST00000453321.8	c.2556+1G>A		splice_donor_variant		1	NM_153704.6	ENSP00000389998	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1427410 Hom.: 0 Cov.: 24 AF XY: 0.00 AC XY: 0 AN XY: 712318

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000468 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

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

Apr 08, 2023

For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. Disruption of this splice site has been observed in individual(s) with Joubert syndrome and related disorders (PMID: 21068128). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 24 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). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D
GERP RS		5.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.96		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.96		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs786200867; hg19: chr8-94821185;