chr7-144453600-A-T

Variant names:

• chr7-144453600-A-T
• rs550639617
• NM_022445.4:c.677T>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM1 BP4_Strong

The NM_022445.4(TPK1):​c.677T>A​(p.Val226Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,613,964 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V226I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: TPK1 NM_022445.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.63
• Publications: 3 publications found

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 Gene-Disease associations (from GenCC):

• childhood encephalopathy due to thiamine pyrophosphokinase deficiency

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia
• Leigh syndrome

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -2 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, 8 uncertain in NM_022445.4
• BP4: Computational evidence support a benign effect (MetaRNN=0.05386299).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_022445.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TPK1	NM_022445.4	MANE Select	c.677T>A	p.Val226Asp	missense	Exon 9 of 9	NP_071890.2
	TPK1	NM_001350879.1		c.677T>A	p.Val226Asp	missense	Exon 9 of 9	NP_001337808.1	Q9H3S4-1
	TPK1	NM_001350882.1		c.662T>A	p.Val221Asp	missense	Exon 10 of 10	NP_001337811.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TPK1	ENST00000360057.7	TSL:1 MANE Select	c.677T>A	p.Val226Asp	missense	Exon 9 of 9	ENSP00000353165.3	Q9H3S4-1
	TPK1	ENST00000378098.8	TSL:1	n.*433T>A		non_coding_transcript_exon	Exon 10 of 10	ENSP00000367338.4	F8WCM7
	TPK1	ENST00000482940.5	TSL:1	n.*708T>A		non_coding_transcript_exon	Exon 12 of 12	ENSP00000449909.1	F8VVJ1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152210 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000278 AC: 7 AN: 251402 AF XY: 0.0000368

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000381

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461636 Hom.: 0 Cov.: 30 AF XY: 0.00000688 AC XY: 5 AN XY: 727130

African (AFR) AF: 0.00 AC: 0 AN: 33458

American (AMR) AF: 0.00 AC: 0 AN: 44706

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.000227 AC: 9 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111836

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome AF: 0.00000656 AC: 1 AN: 152328 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74486

African (AFR) AF: 0.00 AC: 0 AN: 41564

American (AMR) AF: 0.00 AC: 0 AN: 15296

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68034

Other (OTH) AF: 0.00 AC: 0 AN: 2116

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ExAC AF: 0.0000247 AC: 3

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Childhood encephalopathy due to thiamine pyrophosphokinase deficiency (1)
-	1	-	Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.12	T
BayesDel_noAF	Benign	-0.10
CADD	Benign	22
DANN	Benign	0.85
DEOGEN2	Benign	0.40	T
Eigen	Benign	-0.42
Eigen_PC	Benign	-0.30
FATHMM_MKL	Benign	0.17	N
M_CAP	Benign	0.022	T
MetaRNN	Benign	0.054	T
MetaSVM	Benign	-0.76	T
MutationAssessor	Uncertain	2.4	M
PhyloP100		2.6
PrimateAI	Benign	0.39	T
PROVEAN	Benign	-1.8	N
REVEL	Uncertain	0.42
Sift	Benign	0.57	T
Sift4G	Benign	0.60	T
Polyphen		0.0010	B
Vest4		0.44
MutPred		0.53		Gain of disorder (P = 0.0064)
MVP		0.35
MPC		0.25
ClinPred		0.12	T
GERP RS		4.6
Varity_R		0.71
gMVP		0.68
Mutation Taster		=72/28	polymorphism

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

Other links and lift over

dbSNP: rs550639617; hg19: chr7-144150693;