7-144453615-T-C

Variant summary

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

The NM_022445.4(TPK1):c.662A>G(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 (★). Synonymous variant affecting the same amino acid position (i.e. Y221Y) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

TPK1
NM_022445.4 missense

Scores

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]

TPK1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain 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	UniProt
TPK1	NM_022445.4 linkuse as main transcript	c.662A>G	p.Tyr221Cys	missense_variant	9/9	ENST00000360057.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TPK1	ENST00000360057.7 linkuse as main transcript	c.662A>G	p.Tyr221Cys	missense_variant	9/9	1	NM_022445.4	P1	Q9H3S4-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251400

Hom.:

AF XY:

0.00000736

AC XY:

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:

AN:

1461644

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

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.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

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 submitter

clinical testing

Invitae

Mar 06, 2020

This 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

BayesDel_noAF

Pathogenic

0.28

Cadd

Uncertain

Dann

Uncertain

1.0

DEOGEN2

Uncertain

0.64

D;D;.

Eigen

Uncertain

0.67

Eigen_PC

Uncertain

0.65

FATHMM_MKL

Uncertain

0.90

M_CAP

Uncertain

0.14

MetaRNN

Pathogenic

0.90

D;D;D

MetaSVM

Uncertain

0.17

MutationAssessor

Pathogenic

2.9

M;.;.

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Uncertain

0.71

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

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over