rs750322523

Variant names:

• chr7-144453615-T-C
• rs750322523
• NM_022445.4:c.662A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_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
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.19
• Publications: 2 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 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, 8 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

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.662A>G	p.Tyr221Cys	missense	Exon 9 of 9	NP_071890.2
	TPK1	NM_001350879.1		c.662A>G	p.Tyr221Cys	missense	Exon 9 of 9	NP_001337808.1	Q9H3S4-1
	TPK1	NM_001350882.1		c.647A>G	p.Tyr216Cys	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.662A>G	p.Tyr221Cys	missense	Exon 9 of 9	ENSP00000353165.3	Q9H3S4-1
	TPK1	ENST00000378098.8	TSL:1	n.*418A>G		non_coding_transcript_exon	Exon 10 of 10	ENSP00000367338.4	F8WCM7
	TPK1	ENST00000482940.5	TSL:1	n.*693A>G		non_coding_transcript_exon	Exon 12 of 12	ENSP00000449909.1	F8VVJ1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251400 AF XY: 0.00000736

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 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

African (AFR) AF: 0.00 AC: 0 AN: 33460

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

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: 5768

European-Non Finnish (NFE) AF: 0.0000144 AC: 16 AN: 1111828

Other (OTH) AF: 0.00 AC: 0 AN: 60386

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

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

Computational scores

Source: dbNSFP v4.9

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
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
MetaSVM	Uncertain	0.17	D
MutationAssessor	Pathogenic	2.9	M
PhyloP100		5.2
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-6.3	D
REVEL	Pathogenic	0.70
Sift	Uncertain	0.016	D
Sift4G	Uncertain	0.0060	D
Polyphen		1.0	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
Mutation Taster		=49/51	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

dbSNP: rs750322523; hg19: chr7-144150708;