rs142938748

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PM5PP3_Moderate

The NM_144596.4(TTC8):​c.1253A>C​(p.Gln418Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,708 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q418R) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)
Exomes š‘“: 6.8e-7 ( 0 hom. )

Consequence

TTC8
NM_144596.4 missense

Scores

6
9
2

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 8.88
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 Likely_pathogenic. Variant got 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr14-88872358-A-G is described in Lovd as [Likely_pathogenic].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.853

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTC8NM_144596.4 linkc.1253A>C p.Gln418Pro missense_variant Exon 13 of 15 ENST00000380656.7 NP_653197.2 Q8TAM2-4Q86U25

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTC8ENST00000380656.7 linkc.1253A>C p.Gln418Pro missense_variant Exon 13 of 15 2 NM_144596.4 ENSP00000370031.2 Q8TAM2-4

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461708
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727164
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:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.33
D
BayesDel_noAF
Pathogenic
0.23
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Benign
0.25
T;T;T;.;.;T;T;.;.
Eigen
Uncertain
0.57
Eigen_PC
Uncertain
0.62
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.96
D;D;D;D;D;.;.;D;.
M_CAP
Uncertain
0.091
D
MetaRNN
Pathogenic
0.85
D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
-0.087
T
PrimateAI
Uncertain
0.54
T
PROVEAN
Pathogenic
-5.2
.;.;D;.;.;D;D;D;D
REVEL
Pathogenic
0.71
Sift
Uncertain
0.0030
.;.;D;.;.;D;D;D;D
Sift4G
Uncertain
0.0070
D;D;D;D;D;D;D;D;D
Polyphen
1.0
.;.;.;D;.;.;.;D;D
Vest4
0.88
MVP
0.73
MPC
0.56
ClinPred
1.0
D
GERP RS
5.6
gMVP
0.86

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.050
Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr14-89338702; API