chr7-144453620-A-T

Variant names:

• chr7-144453620-A-T
• NM_022445.4:c.657T>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_022445.4(TPK1):​c.657T>A​(p.Asn219Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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. N219S) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TPK1 NM_022445.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0680
• Publications: 0 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_pathogenic. The variant received 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-144453621-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 30572.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.968

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.657T>A	p.Asn219Lys	missense	Exon 9 of 9	NP_071890.2
	TPK1	NM_001350879.1		c.657T>A	p.Asn219Lys	missense	Exon 9 of 9	NP_001337808.1	Q9H3S4-1
	TPK1	NM_001350882.1		c.642T>A	p.Asn214Lys	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.657T>A	p.Asn219Lys	missense	Exon 9 of 9	ENSP00000353165.3	Q9H3S4-1
	TPK1	ENST00000378098.8	TSL:1	n.*413T>A		non_coding_transcript_exon	Exon 10 of 10	ENSP00000367338.4	F8WCM7
	TPK1	ENST00000482940.5	TSL:1	n.*688T>A		non_coding_transcript_exon	Exon 12 of 12	ENSP00000449909.1	F8VVJ1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D
Eigen	Uncertain	0.39
Eigen_PC	Benign	0.19
FATHMM_MKL	Benign	0.56	D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.7	H
PhyloP100		-0.068
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-5.5	D
REVEL	Pathogenic	0.83
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0030	D
Polyphen		1.0	D
Vest4		0.94
MutPred		0.75		Gain of ubiquitination at N219 (P = 0.0121)
MVP		0.80
MPC		0.71
ClinPred		1.0	D
GERP RS		-2.2
Varity_R		0.99
gMVP		0.97
Mutation Taster		=21/79	disease causing

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

hg19: chr7-144150713;