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rs79747892

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 splice polypyrimidine tract, 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 splice_polypyrimidine_tract, intron

Scores

2
Splicing: ADA: 0.0001204
2

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]

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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/exons MANE UniProt
TTC8NM_144596.4 linkuse as main transcriptc.1432-12T>C splice_polypyrimidine_tract_variant, intron_variant ENST00000380656.7

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TTC8ENST00000380656.7 linkuse as main transcriptc.1432-12T>C splice_polypyrimidine_tract_variant, intron_variant 2 NM_144596.4 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
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.:
29
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.:
33
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.:
16
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
Benign, no assertion criteria providedclinical testingGenome Diagnostics Laboratory, Amsterdam University Medical Center-- -
Benign, criteria provided, single submitterclinical testingPreventionGenetics, part of Exact Sciences-- -
Benign, no assertion criteria providedclinical testingClinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center-- -
Benign, no assertion criteria providedclinical testingGenome Diagnostics Laboratory, University Medical Center Utrecht-- -
Bardet-Biedl syndrome 8 Benign:1
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 2018This 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
Benign, criteria provided, single submitterclinical testingInvitaeJan 31, 2024- -
Retinitis pigmentosa Benign:1
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 2018This 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

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.

Other links and lift over

dbSNP: rs79747892; hg19: chr14-89343626; API