1-39844131-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_017646.6(TRIT1):c.1204C>T(p.Arg402Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000682 in 1,613,908 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: TRIT1 NM_017646.6 stop_gained
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:3
• Conservation: PhyloP100: 3.83

Genes affected

TRIT1 (HGNC:20286): (tRNA isopentenyltransferase 1) This gene encodes a protein that that is targeted to the mitochondrion and modifies transfer RNAs (tRNAs) by adding a dimethylallyl group onto the adenine at position 37. This modification is important for maintaining the correct reading frame during protein translation. This gene is considered a tumor suppressor and its expression can decrease cell growth. Alternative splicing results in multiple transcripts variants, most of which are likely non-functional. [provided by RefSeq, Aug 2015]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-39844131-G-A is Pathogenic according to our data. Variant chr1-39844131-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 417682.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Uncertain_significance=2}. Variant chr1-39844131-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TRIT1	NM_017646.6	c.1204C>T	p.Arg402Ter	stop_gained	10/11	ENST00000316891.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TRIT1	ENST00000316891.10	c.1204C>T	p.Arg402Ter	stop_gained	10/11	1	NM_017646.6	P1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152114 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251412 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135878

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 SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461676 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727154

Gnomad4 AFR exome AF: 0.0000299

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: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152232 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74422

Gnomad4 AFR AF: 0.0000481

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ExAC AF: 0.0000165 AC: 2

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Combined oxidative phosphorylation deficiency 35 Pathogenic:2 Uncertain:1

Pathogenic, no assertion criteria provided	literature only	OMIM	Feb 16, 2018	- -
Uncertain significance, criteria provided, single submitter	curation	SIB Swiss Institute of Bioinformatics	Oct 15, 2018	This variant is interpreted as Uncertain Significance - Insufficient Evidence, for Combined oxidative phosphorylation deficiency 35, autosomal recessive. The following ACMG Tag(s) were applied: PM2 => Absent from controls (or at extremely low frequency if recessive) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium. PVS1-Moderate => PVS1 downgraded in strength to Moderate. -
Pathogenic, criteria provided, single submitter	clinical testing	Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences	-	- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 15, 2021

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); Nonsense variant predicted to result in protein truncation, although loss-of-function variants have not been reported downstream of this position in the protein; This variant is associated with the following publications: (PMID: 28185376) -

TRIT1 Deficiency Uncertain:1

Uncertain significance, no assertion criteria provided

research

Care4Rare-SOLVE, CHEO

-

This variant was seen in a heterozygous state with c.1256A>C. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.63
Cadd	Pathogenic	37
Dann	Uncertain	1.0
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Uncertain	0.96	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D
Vest4		0.39
GERP RS		5.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs367752391; hg19: chr1-40309803; COSMIC: COSV57549655; COSMIC: COSV57549655;