8-93804796-G-C

Variant names:

• chr8-93804796-G-C
• rs386834193
• NM_153704.6:c.2357G>C

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2 PM5 PP3_Strong PP5

The NM_153704.6(TMEM67):​c.2357G>C​(p.Gly786Ala) variant causes a missense 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. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G786E) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 30)
• Consequence: TMEM67 NM_153704.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 9.47

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 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr8-93804796-G-A is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.971
• PP5: Variant 8-93804796-G-C is Pathogenic according to our data. Variant chr8-93804796-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 684615.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMEM67	NM_153704.6	c.2357G>C	p.Gly786Ala	missense_variant	Exon 23 of 28	ENST00000453321.8	NP_714915.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMEM67	ENST00000453321.8	c.2357G>C	p.Gly786Ala	missense_variant	Exon 23 of 28	1	NM_153704.6	ENSP00000389998.3

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 30

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Meckel syndrome, type 3 Pathogenic:1

-

Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

not specified Uncertain:1

Dec 03, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: TMEM67 c.2357G>C (p.Gly786Ala) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250790 control chromosomes. c.2357G>C has been reported in the literature in at least one homozygous fetus affected with Meckel syndrome (e.g. Radhakrishnan_2019). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 31411728). ClinVar contains an entry for this variant (Variation ID: 684615). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.84
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.99
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D
M_CAP	Pathogenic	0.50	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.0	M;.
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-5.1	D;D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.97
MutPred		0.85		Loss of ubiquitination at K783 (P = 0.1343);.;
MVP		1.0
MPC		0.59
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.92
gMVP		0.94

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.47		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.47		Position offset: -34

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

Publications

LitVar

Other links and lift over

dbSNP: rs386834193; hg19: chr8-94817024;