rs863225224

Positions:

• chr8-93793299-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP3_Moderate PP5

The NM_153704.6(TMEM67):​c.1674+3A>G variant causes a splice donor region, intron change. The variant allele was found at a frequency of 0.000000688 in 1,454,544 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: TMEM67 NM_153704.6 splice_donor_region, intron
• Scores: Splicing: ADA: 0.9998
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 6.31

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 Uncertain_significance. Variant got 5 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 8-93793299-A-G is Pathogenic according to our data. Variant chr8-93793299-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 217707.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}. Variant chr8-93793299-A-G is described in Lovd as [Pathogenic]. Variant chr8-93793299-A-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TMEM67	NM_153704.6	c.1674+3A>G		splice_donor_region_variant, intron_variant		ENST00000453321.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TMEM67	ENST00000453321.8	c.1674+3A>G		splice_donor_region_variant, intron_variant		1	NM_153704.6	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.88e-7 AC: 1 AN: 1454544 Hom.: 0 Cov.: 28 AF XY: 0.00 AC XY: 0 AN XY: 724142

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: 9.05e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Joubert syndrome 6 Pathogenic:1

Pathogenic, criteria provided, single submitter

research

UW Hindbrain Malformation Research Program, University of Washington

Feb 23, 2015

- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 11, 2023

This sequence change falls in intron 16 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 not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with Joubert syndrome with congenital hepatic fibrosis (PMID: 19574260). ClinVar contains an entry for this variant (Variation ID: 217707). 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. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.30
CADD	Benign	12
DANN	Benign	0.96

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.91
SpliceAI score (max)		0.73		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.73		Position offset: -3

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

Publications

LitVar

Other links and lift over

dbSNP: rs863225224; hg19: chr8-94805527;