rs79747892

Variant summary

Our verdict is Benign. The variant received -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

2
Splicing: ADA: 0.0001204
2

Clinical Significance

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

Conservation

PhyloP100: 0.638

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -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 VariationId is 262514.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
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
TTC8NM_144596.4 linkc.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
TTC8ENST00000380656.7 linkc.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.:
33
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
GnomAD2 exomes
AF:
0.00866
AC:
2160
AN:
249516
AF XY:
0.00630
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 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.:
29
AF XY:
0.00291
AC XY:
2108
AN XY:
724162
show subpopulations
African (AFR)
AF:
0.119
AC:
3959
AN:
33296
American (AMR)
AF:
0.00688
AC:
307
AN:
44632
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26082
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39556
South Asian (SAS)
AF:
0.000163
AC:
14
AN:
86094
European-Finnish (FIN)
AF:
0.0000375
AC:
2
AN:
53372
Middle Eastern (MID)
AF:
0.00452
AC:
26
AN:
5748
European-Non Finnish (NFE)
AF:
0.000185
AC:
205
AN:
1105774
Other (OTH)
AF:
0.00691
AC:
415
AN:
60100
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.501
Heterozygous variant carriers
0
215
431
646
862
1077
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
124
248
372
496
620
<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:
0.0334
AC:
5087
AN:
152274
Hom.:
298
Cov.:
33
AF XY:
0.0317
AC XY:
2363
AN XY:
74464
show subpopulations
African (AFR)
AF:
0.116
AC:
4821
AN:
41544
American (AMR)
AF:
0.0126
AC:
193
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.000414
AC:
2
AN:
4828
European-Finnish (FIN)
AF:
0.0000941
AC:
1
AN:
10624
Middle Eastern (MID)
AF:
0.00340
AC:
1
AN:
294
European-Non Finnish (NFE)
AF:
0.000426
AC:
29
AN:
68016
Other (OTH)
AF:
0.0189
AC:
40
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.502
Heterozygous variant carriers
0
227
455
682
910
1137
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
50
100
150
200
250
<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:
0.0155
Hom.:
31
Bravo
AF:
0.0378
Asia WGS
AF:
0.00462
AC:
16
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
-
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
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, 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

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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.74
CADD
Benign
6.2
DANN
Benign
0.80
PhyloP100
0.64
Mutation Taster
=100/0
polymorphism (auto)

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

Other links and lift over

dbSNP: rs79747892; hg19: chr14-89343626; API