Genetic Variant TTC8:p.Met1? (chr14-88824709-T-G) – ACMG Classification: Uncertain_significance (1 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PVS1_Supporting

The NM_144596.4(TTC8):c.2T>G(p.Met1?) variant causes a start lost change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000685 in 1,606,386 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 (no stars).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

TTC8
NM_144596.4 start_lost

Scores

Clinical Significance

Uncertain significance no assertion criteria provided U:1

Conservation

PhyloP100: 2.97

Publications

0 publications found

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 Gene-Disease associations (from GenCC):

Bardet-Biedl syndrome 8
Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P
retinitis pigmentosa 51
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
TTC8-related ciliopathy
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
retinitis pigmentosa
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Bardet-Biedl syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

TTC8 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PVS1

Start lost variant, no pathogenic variants between lost start and next in-frame start position. Next in-frame start position is after 5 codons. Genomic position: 88824720. Lost 0.008 part of the original CDS.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_144596.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
TTC8	NM_144596.4	MANE Select	c.2T>G	p.Met1?	start_lost	Exon 1 of 15	NP_653197.2
TTC8	NM_001288781.1		c.2T>G	p.Met1?	start_lost	Exon 2 of 16	NP_001275710.1	Q86U25
TTC8	NM_198309.3		c.2T>G	p.Met1?	start_lost	Exon 2 of 15	NP_938051.1	A0A0C4DGY3

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
TTC8	ENST00000380656.7	TSL:2 MANE Select	c.2T>G	p.Met1?	start_lost	Exon 1 of 15	ENSP00000370031.2	Q8TAM2-4
TTC8	ENST00000338104.10	TSL:1	c.2T>G	p.Met1?	start_lost	Exon 1 of 15	ENSP00000337653.6	A0A0C4DGX9
TTC8	ENST00000622513.4	TSL:1	c.2T>G	p.Met1?	start_lost	Exon 1 of 14	ENSP00000482721.1	A0A0C4DGY3

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152108

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000429

AC:

AN:

232976

AF XY:

0.00

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000961

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000619

AC:

AN:

1454278

Hom.:

Cov.:

AF XY:

0.00000692

AC XY:

AN XY:

722790

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33348

American (AMR)

AF:

0.00

AC:

AN:

43932

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25928

East Asian (EAS)

AF:

0.00

AC:

AN:

39502

South Asian (SAS)

AF:

0.00

AC:

AN:

84954

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52246

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5362

European-Non Finnish (NFE)

AF:

0.00000812

AC:

AN:

1108938

Other (OTH)

AF:

0.00

AC:

AN:

60068

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152108

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74316

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41432

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3460

East Asian (EAS)

AF:

0.00

AC:

AN:

5162

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10610

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68006

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ClinVar

ClinVar submissions

Significance:Uncertain significance

Revision:no assertion criteria provided

View on ClinVar

Pathogenic

VUS

Benign

Condition

TTC8-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

PhyloP100

3.0

PromoterAI

-0.68

Under-expression

(source)

gMVP

0.59

Mutation Taster

=60/140

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over