dbSNP rs79747892: TTC8:c.1432-12T>C (chr14-88877282-T-C) – ACMG Classification: Benign (-20 pts)

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBA1

The NM_144596.4(TTC8):c.1432-12T>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00623 in 1,606,928 control chromosomes in the GnomAD database, including 560 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.033 ( 298 hom., cov: 33)

Exomes 𝑓: 0.0034 ( 262 hom. )

Consequence

TTC8
NM_144596.4 intron

Scores

Splicing: ADA: 0.0001204

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:7

Conservation

PhyloP100: 0.638

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 Benign. Variant got -20 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.74).

BP6

Variant 14-88877282-T-C is Benign according to our data. Variant chr14-88877282-T-C is described in ClinVar as [Benign]. Clinvar id is 262514.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr14-88877282-T-C is described in Lovd as [Benign].

BA1

GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.113 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC8	NM_144596.4 link	c.1432-12T>C		intron_variant	Intron 14 of 14	ENST00000380656.7	NP_653197.2	Q8TAM2-4Q86U25

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTC8	ENST00000380656.7 link	c.1432-12T>C		intron_variant	Intron 14 of 14	2	NM_144596.4	ENSP00000370031.2		Q8TAM2-4

Frequencies

GnomAD3 genomes

AF:

0.0334

AC:

5081

AN:

152156

Hom.:

297

Cov.:

show subpopulations

Gnomad AFR

AF:

0.116

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0126

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000621

Gnomad FIN

AF:

0.0000941

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.000426

Gnomad OTH

AF:

0.0191

GnomAD3 exomes

AF:

0.00866

AC:

2160

AN:

249516

Hom.:

126

AF XY:

0.00630

AC XY:

850

AN XY:

134898

show subpopulations

Gnomad AFR exome

AF:

0.116

Gnomad AMR exome

AF:

0.00616

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000164

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000329

Gnomad OTH exome

AF:

0.00477

GnomAD4 exome

AF:

0.00339

AC:

4928

AN:

1454654

Hom.:

262

Cov.:

AF XY:

0.00291

AC XY:

2108

AN XY:

724162

show subpopulations

Gnomad4 AFR exome

AF:

0.119

Gnomad4 AMR exome

AF:

0.00688

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000163

Gnomad4 FIN exome

AF:

0.0000375

Gnomad4 NFE exome

AF:

0.000185

Gnomad4 OTH exome

AF:

0.00691

GnomAD4 genome

AF:

0.0334

AC:

5087

AN:

152274

Hom.:

298

Cov.:

AF XY:

0.0317

AC XY:

2363

AN XY:

74464

show subpopulations

Gnomad4 AFR

AF:

0.116

Gnomad4 AMR

AF:

0.0126

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000414

Gnomad4 FIN

AF:

0.0000941

Gnomad4 NFE

AF:

0.000426

Gnomad4 OTH

AF:

0.0189

Alfa

AF:

0.0157

Hom.:

Bravo

AF:

0.0378

Asia WGS

AF:

0.00462

AC:

AN:

3478

ClinVar

Significance: Benign

Submissions summary: Benign:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:4

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

PreventionGenetics, part of Exact Sciences

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Genome Diagnostics Laboratory, University Medical Center Utrecht

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Genome Diagnostics Laboratory, Amsterdam University Medical Center

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Bardet-Biedl syndrome 8

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Bardet-Biedl syndrome

Benign:1

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Retinitis pigmentosa

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.74

CADD

Benign

6.2

DANN

Benign

0.80

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.00012

dbscSNV1_RF

Benign

0.0020

SpliceAI score (max)

0.010

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