chr7-144453615-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_022445.4(TPK1):ā€‹c.662A>Gā€‹(p.Tyr221Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000109 in 1,461,644 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 Uncertain significance (ā˜…).

Frequency

Genomes: not found (cov: 32)
Exomes š‘“: 0.000011 ( 0 hom. )

Consequence

TPK1
NM_022445.4 missense

Scores

6
10
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.19
Variant links:
Genes affected
TPK1 (HGNC:17358): (thiamin pyrophosphokinase 1) The protein encoded by this gene functions as a homodimer and catalyzes the conversion of thiamine to thiamine pyrophosphate, a cofactor for some enzymes of the glycolytic and energy production pathways. Defects in this gene are a cause of thiamine metabolism dysfunction syndrome-5. [provided by RefSeq, Apr 2017]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM1
In a chain Thiamin pyrophosphokinase 1 (size 242) in uniprot entity TPK1_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) in NM_022445.4
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.899

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TPK1NM_022445.4 linkuse as main transcriptc.662A>G p.Tyr221Cys missense_variant 9/9 ENST00000360057.7 NP_071890.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TPK1ENST00000360057.7 linkuse as main transcriptc.662A>G p.Tyr221Cys missense_variant 9/91 NM_022445.4 ENSP00000353165 P1Q9H3S4-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251400
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135868
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000109
AC:
16
AN:
1461644
Hom.:
0
Cov.:
30
AF XY:
0.00000963
AC XY:
7
AN XY:
727142
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000144
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Childhood encephalopathy due to thiamine pyrophosphokinase deficiency Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpMar 06, 2020This variant has not been reported in the literature in individuals with TPK1-related conditions. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant is present in population databases (rs750322523, ExAC 0.001%). This sequence change replaces tyrosine with cysteine at codon 221 of the TPK1 protein (p.Tyr221Cys). The tyrosine residue is moderately conserved and there is a large physicochemical difference between tyrosine and cysteine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.32
BayesDel_addAF
Pathogenic
0.36
D
BayesDel_noAF
Pathogenic
0.28
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.64
D;D;.
Eigen
Uncertain
0.67
Eigen_PC
Uncertain
0.65
FATHMM_MKL
Uncertain
0.90
D
M_CAP
Uncertain
0.14
D
MetaRNN
Pathogenic
0.90
D;D;D
MetaSVM
Uncertain
0.17
D
MutationAssessor
Pathogenic
2.9
M;.;.
MutationTaster
Benign
1.0
D;D;D;D
PrimateAI
Uncertain
0.71
T
PROVEAN
Pathogenic
-6.3
D;D;D
REVEL
Pathogenic
0.70
Sift
Uncertain
0.016
D;D;D
Sift4G
Uncertain
0.0060
D;D;D
Polyphen
1.0
D;D;D
Vest4
0.81
MVP
0.87
MPC
0.73
ClinPred
0.99
D
GERP RS
5.5
Varity_R
0.79
gMVP
0.78

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs750322523; hg19: chr7-144150708; API