rs797044454

Positions:

• chr22-50528510-A-G
• chr22-50528510-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_001953.5(TYMP):​c.516+2T>C variant causes a splice donor change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: TYMP NM_001953.5 splice_donor
• Scores: Splicing: ADA: 0.9880
• Clinical Significance: Pathogenic no assertion criteria provided P:2
• Conservation: PhyloP100: 4.01

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.06763285 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.8, offset of 33, new splice context is: cagGTtgat. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-50528510-A-G is Pathogenic according to our data. Variant chr22-50528510-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 16654.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TYMP	NM_001953.5	c.516+2T>C		splice_donor_variant		ENST00000252029.8	NP_001944.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TYMP	ENST00000252029.8	c.516+2T>C		splice_donor_variant		1	NM_001953.5	ENSP00000252029	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000468 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: no assertion criteria provided

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	literature only	OMIM	Jan 29, 1999	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Uncertain	0.11
CADD	Uncertain	24
DANN	Uncertain	0.99
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Uncertain	0.90	D
MutationTaster	Benign	1.0	D;D;D;D
GERP RS		4.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.75
SpliceAI score (max)		0.78		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.78		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs797044454; hg19: chr22-50966939;