Genetic Variant TTC39C:p.Met266Leu (chr18-24080920-A-C) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001135993.2(TTC39C):c.796A>C(p.Met266Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,888 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TTC39C
NM_001135993.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.94

Variant links:

Genes affected

TTC39C (HGNC:26595): (tetratricopeptide repeat domain 39C) Predicted to be involved in cilium assembly and otolith morphogenesis. [provided by Alliance of Genome Resources, Apr 2022]

TTC39C links:

ENSG00000265204 (HGNC:):

ENSG00000265204 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC39C	NM_001135993.2 link	c.796A>C	p.Met266Leu	missense_variant	Exon 5 of 14	ENST00000317571.8	NP_001129465.1	Q8N584-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
TTC39C	ENST00000317571.8 link	c.796A>C	p.Met266Leu	missense_variant	Exon 5 of 14	1	NM_001135993.2	ENSP00000323645.3	Q8N584-1
TTC39C	ENST00000304621.10 link	c.613A>C	p.Met205Leu	missense_variant	Exon 5 of 14	1		ENSP00000306598.6	Q8N584-2
ENSG00000265204	ENST00000578443.1 link	n.99-3661T>G		intron_variant	Intron 1 of 1	4
TTC39C	ENST00000578150.1 link	n.*141A>C		downstream_gene_variant		3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000403

AC:

AN:

248050

Hom.:

AF XY:

0.00

AC XY:

AN XY:

134314

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000900

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1460888

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726746

show subpopulations

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:

9.00e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jul 16, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.796A>C (p.M266L) alteration is located in exon 5 (coding exon 5) of the TTC39C gene. This alteration results from a A to C substitution at nucleotide position 796, causing the methionine (M) at amino acid position 266 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.82

BayesDel_addAF

Uncertain

0.11

BayesDel_noAF

Uncertain

-0.070

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Benign

0.090

.;T

Eigen

Uncertain

0.68

Eigen_PC

Pathogenic

0.71

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.97

D;D

M_CAP

Benign

0.027

MetaRNN

Uncertain

0.44

T;T

MetaSVM

Benign

-0.89

MutationAssessor

Uncertain

2.6

.;M

PrimateAI

Pathogenic

0.83

PROVEAN

Benign

-2.3

N;N

REVEL

Benign

0.16

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

0.88

.;P

Vest4

0.56

MutPred

0.46

.;Loss of ubiquitination at K267 (P = 0.0863);

MVP

0.64

MPC

1.2

ClinPred

0.92

GERP RS

5.9

Varity_R

0.81

gMVP

0.65

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over