chr22-50526316-TC-T

Position:

• chr22-50526316-TC-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001953.5(TYMP):​c.1088delG​(p.Gly363fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. 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: 34)
• Consequence: TYMP NM_001953.5 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:3
• Conservation: PhyloP100: 0.325

Genes affected

TYMP (HGNC:3148): (thymidine phosphorylase) This gene encodes an angiogenic factor which promotes angiogenesis in vivo and stimulates the in vitro growth of a variety of endothelial cells. It has a highly restricted target cell specificity acting only on endothelial cells. Mutations in this gene have been associated with mitochondrial neurogastrointestinal encephalomyopathy. Multiple alternatively spliced transcript variants have been identified. [provided by RefSeq, Apr 2012]

SCO2 (HGNC:10604): (synthesis of cytochrome C oxidase 2) Cytochrome c oxidase (COX) catalyzes the transfer of electrons from cytochrome c to molecular oxygen, which helps to maintain the proton gradient across the inner mitochondrial membrane that is necessary for aerobic ATP production. Human COX is a multimeric protein complex that requires several assembly factors; this gene encodes one of the COX assembly factors. The encoded protein is a metallochaperone that is involved in the biogenesis of cytochrome c oxidase subunit II. Mutations in this gene are associated with fatal infantile encephalocardiomyopathy and myopia 6. [provided by RefSeq, Oct 2014]

TYMP (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 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 22-50526316-TC-T is Pathogenic according to our data. Variant chr22-50526316-TC-T is described in ClinVar as [Pathogenic]. Clinvar id is 223083.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TYMP	NM_001953.5	c.1088delG	p.Gly363fs	frameshift_variant	8/10	ENST00000252029.8	NP_001944.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TYMP	ENST00000252029.8	c.1088delG	p.Gly363fs	frameshift_variant	8/10	1	NM_001953.5	ENSP00000252029.3

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 34

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, single submitter

Submissions by phenotype

Mitochondrial DNA depletion syndrome 1 Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	GeneReviews	Jan 14, 2016	- -
Pathogenic, no assertion criteria provided	clinical testing	Genomics England Pilot Project, Genomics England	-	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 06, 2024

This sequence change results in a frameshift in the TYMP gene (p.Gly363Glufs*). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 120 amino acid(s) of the TYMP protein and extend the protein by an uncertain number of additional amino acid residues. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TYMP-related conditions. ClinVar contains an entry for this variant (Variation ID: 223083). This variant results in an extension of the TYMP protein. Other variant(s) that result in a similarly extended protein product (p.Phe473Serfs*?) have been determined to be pathogenic (PMID: 21412940). This suggests that these extensions are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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: rs1060499535; hg19: chr22-50964745;