rs794726691

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_017775.4(TTC19):​c.601_604delGGCT​(p.Gly201MetfsTer8) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000021 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

TTC19
NM_017775.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 5.86

Publications

2 publications found
Variant links:
Genes affected
TTC19 (HGNC:26006): (tetratricopeptide repeat domain 19) This gene encodes a protein with a tetratricopeptide repeat (TPR) domain containing several TPRs of about 34 aa each. These repeats are found in a variety of organisms including bacteria, fungi and plants, and are involved in a variety of functions including protein-protein interactions. This protein is embedded in the inner mitochondrial membrane and is involved in the formation of the mitochondrial respiratory chain III. It has also been suggested that this protein plays a role in cytokinesis. Mutations in this gene cause mitochondrial complex III deficiency. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Sep 2012]
TTC19 Gene-Disease associations (from GenCC):
  • Leigh syndrome
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • mitochondrial complex III deficiency nuclear type 2
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
  • mitochondrial complex III deficiency
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 17-16006489-TGCTG-T is Pathogenic according to our data. Variant chr17-16006489-TGCTG-T is described in ClinVar as Pathogenic. ClinVar VariationId is 102437.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTC19NM_017775.4 linkc.601_604delGGCT p.Gly201MetfsTer8 frameshift_variant Exon 7 of 10 ENST00000261647.10 NP_060245.3 Q6DKK2A0A024RD83

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTC19ENST00000261647.10 linkc.601_604delGGCT p.Gly201MetfsTer8 frameshift_variant Exon 7 of 10 1 NM_017775.4 ENSP00000261647.5 Q6DKK2
TTC19ENST00000475723.5 linkn.*285_*288delGGCT non_coding_transcript_exon_variant Exon 7 of 10 2 ENSP00000465754.1 K7EKS0
TTC19ENST00000497842.6 linkn.711_714delGGCT non_coding_transcript_exon_variant Exon 6 of 10 5
TTC19ENST00000475723.5 linkn.*285_*288delGGCT 3_prime_UTR_variant Exon 7 of 10 2 ENSP00000465754.1 K7EKS0

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251456
AF XY:
0.00000736
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:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
0.00000205
AC:
3
AN:
1460142
Hom.:
0
AF XY:
0.00000275
AC XY:
2
AN XY:
726516
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33458
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26122
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86218
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5590
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1110620
Other (OTH)
AF:
0.00
AC:
0
AN:
60310
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
Cov.:
33
Alfa
AF:
0.0000508
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:3
Nov 02, 2017
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.601_604delGGCT variant in the TTC19 gene has been reported previously in the homozygous and heterozygous states with a second TTC19 variant in association with mitochondrial complex III deficiency; note that c.601_604delGGCT has been reported using alternate nomenclature c.963_966delTGGC and c.964_967delGGCT (Nogueira et al., 2013; Atwal, 2014). The c.601_604delGGCT variant causes a frameshift starting with codon Glycine 201, changes this amino acid to a Methionine residue, and creates a premature Stop codon at position 8 of the new reading frame, denoted p.Gly201MetfsX8. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The c.601_604delGGCT variant is not observed in large population cohorts (Lek et al., 2016). We interpret c.601_604delGGCT as a pathogenic variant. -

Aug 02, 2023
Mayo Clinic Laboratories, Mayo Clinic
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PP1_strong, PM2_moderate, PM3, PS3, PVS1 -

Apr 29, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Gly201Metfs*8) in the TTC19 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in TTC19 are known to be pathogenic (PMID: 21278747, 24368687). This variant is present in population databases (rs794726691, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with mitochondrial complex III deficiency. (PMID: 23532514, 24368687). This variant is also known as p.Gly322MetfsX8 or p.A321Afs*8. ClinVar contains an entry for this variant (Variation ID: 102437). For these reasons, this variant has been classified as Pathogenic. -

Mitochondrial complex III deficiency nuclear type 2 Pathogenic:1
May 01, 2013
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
5.9
Mutation Taster
=2/198
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs794726691; hg19: chr17-15909803; API