22-50528595-C-T

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM1PP3_StrongPP5_Very_Strong

The NM_001953.5(TYMP):​c.433G>A​(p.Gly145Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,613,694 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 Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. G145G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

TYMP
NM_001953.5 missense

Scores

12
4
3

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 2.62

Publications

13 publications found
Variant links:
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]
TYMP Gene-Disease associations (from GenCC):
  • mitochondrial disease
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • mitochondrial DNA depletion syndrome 1
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • mitochondrial neurogastrointestinal encephalomyopathy
    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 14 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 4 uncertain in NM_001953.5
PP3
MetaRNN computational evidence supports a deleterious effect, 0.942
PP5
Variant 22-50528595-C-T is Pathogenic according to our data. Variant chr22-50528595-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 16655.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
TYMPNM_001953.5 linkc.433G>A p.Gly145Arg missense_variant Exon 4 of 10 ENST00000252029.8 NP_001944.1 P19971-1E5KRG5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TYMPENST00000252029.8 linkc.433G>A p.Gly145Arg missense_variant Exon 4 of 10 1 NM_001953.5 ENSP00000252029.3 P19971-1

Frequencies

GnomAD3 genomes
AF:
0.0000723
AC:
11
AN:
152200
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000523
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000160
AC:
4
AN:
250760
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.0000619
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:
0.0000176
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000109
AC:
16
AN:
1461376
Hom.:
0
Cov.:
32
AF XY:
0.0000110
AC XY:
8
AN XY:
726984
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.0000224
AC:
1
AN:
44708
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86190
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53144
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000126
AC:
14
AN:
1111894
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.444
Heterozygous variant carriers
0
1
2
4
5
6
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
AF:
0.0000722
AC:
11
AN:
152318
Hom.:
0
Cov.:
33
AF XY:
0.0000537
AC XY:
4
AN XY:
74480
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41570
American (AMR)
AF:
0.000523
AC:
8
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.470
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.000144
Hom.:
0
Bravo
AF:
0.000106
ExAC
AF:
0.0000412
AC:
5
EpiCase
AF:
0.000109
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Mitochondrial DNA depletion syndrome 1 Pathogenic:7
Mar 29, 2022
MGZ Medical Genetics Center
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 21, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 14, 2016
GeneReviews
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Jul 25, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TYMP c.433G>A (p.Gly145Arg) results in a non-conservative amino acid change located in the Glycosyl transferase, family 3 (IPR000312) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 250760 control chromosomes. c.433G>A has been reported in the literature in multiple individuals affected with Mitochondrial DNA Depletion Syndrome 1 (MNGIE type) (Example: Nishino_1999, Zaidman_2021). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 9924029, 33533561). Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Jan 29, 1999
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Feb 03, 2021
Revvity Omics, Revvity
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 28, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:2
Nov 16, 2022
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; In silico analysis is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: 19748572, 25525159, 9924029, 21820356, 16995425, 20301358, 18787099, 34288589) -

Jun 28, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 145 of the TYMP protein (p.Gly145Arg). This variant is present in population databases (rs121913037, gnomAD 0.007%). This missense change has been observed in individuals with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) (PMID: 9924029, 10852545, 16995425). It has also been observed to segregate with disease in related individuals. This variant is also known as G1419A. ClinVar contains an entry for this variant (Variation ID: 16655). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Not Available". The arginine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Mitochondrial neurogastrointestinal encephalomyopathy Pathogenic:1
Sep 16, 2020
Natera, Inc.
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.89
BayesDel_addAF
Pathogenic
0.36
D
BayesDel_noAF
Pathogenic
0.46
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.98
D;.;D;D
Eigen
Uncertain
0.49
Eigen_PC
Uncertain
0.27
FATHMM_MKL
Benign
0.62
D
LIST_S2
Uncertain
0.90
.;D;.;D
M_CAP
Pathogenic
0.49
D
MetaRNN
Pathogenic
0.94
D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
4.0
H;H;H;H
PhyloP100
2.6
PrimateAI
Benign
0.35
T
PROVEAN
Pathogenic
-7.9
D;D;D;D
REVEL
Pathogenic
0.82
Sift
Pathogenic
0.0
D;D;D;D
Sift4G
Pathogenic
0.0
D;D;D;D
Polyphen
1.0
D;.;D;D
Vest4
0.70
MutPred
0.95
Loss of methylation at R146 (P = 0.027);Loss of methylation at R146 (P = 0.027);Loss of methylation at R146 (P = 0.027);Loss of methylation at R146 (P = 0.027);
MVP
0.93
MPC
1.4
ClinPred
1.0
D
GERP RS
2.4
Varity_R
0.99
gMVP
0.92
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.32
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.32
Position offset: 15

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

Publications

Other links and lift over

dbSNP: rs121913037; hg19: chr22-50967024; API