rs774216735

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_144596.4(TTC8):c.1124A>C(p.Gln375Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000123 in 1,461,840 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. Q375Q) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

TTC8
NM_144596.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.96

Variant links:

Genes affected

TTC8 (HGNC:20087): (tetratricopeptide repeat domain 8) This gene encodes a protein that has been directly linked to Bardet-Biedl syndrome. The primary features of this syndrome include retinal dystrophy, obesity, polydactyly, renal abnormalities and learning disabilities. Experimentation in non-human eukaryotes suggests that this gene is expressed in ciliated cells and that it is involved in the formation of cilia. A mutation in this gene has also been implicated in nonsyndromic retinitis pigmentosa. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2014]

TTC8 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.859

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTC8	NM_144596.4 linkuse as main transcript	c.1124A>C	p.Gln375Pro	missense_variant	12/15	ENST00000380656.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTC8	ENST00000380656.7 linkuse as main transcript	c.1124A>C	p.Gln375Pro	missense_variant	12/15	2	NM_144596.4		Q8TAM2-4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000239

AC:

AN:

251242

Hom.:

AF XY:

0.0000442

AC XY:

AN XY:

135780

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:

0.000196

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000123

AC:

AN:

1461840

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

727228

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:

0.000197

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

ExAC

AF:

0.0000165

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Bardet-Biedl syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 01, 2021

This sequence change replaces glutamine with proline at codon 365 of the TTC8 protein (p.Gln365Pro). The glutamine residue is highly conserved and there is a moderate physicochemical difference between glutamine and proline. This variant is present in population databases (rs774216735, ExAC 0.01%). This variant has not been reported in the literature in individuals affected with TTC8-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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_addAF

Pathogenic

0.18

BayesDel_noAF

Pathogenic

0.29

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Uncertain

0.50

D;T;T;.;.;D;T;.;.

Eigen

Uncertain

0.64

Eigen_PC

Pathogenic

0.68

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.94

D;D;D;D;D;.;.;D;.

M_CAP

Uncertain

0.22

MetaRNN

Pathogenic

0.86

D;D;D;D;D;D;D;D;D

MetaSVM

Uncertain

0.28

MutationTaster

Benign

1.0

D;D;D;D;D;D;D

PrimateAI

Pathogenic

0.83

REVEL

Pathogenic

0.76

Sift4G

Uncertain

0.0040

D;D;D;D;D;D;D;D;D

Polyphen

1.0

.;.;.;D;.;.;.;D;D

Vest4

0.89

MVP

0.77

MPC

0.56

ClinPred

0.91

GERP RS

5.9

gMVP

0.88

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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