rs1554562296

Variant names:

• chr7-144591435-G-A
• rs1554562296
• NM_022445.4:c.489C>T

Variant summary

Our verdict is Benign. The variant received -11 ACMG points: 2P and 13B. PM2 BP4_Strong BP6_Very_Strong BP7

The NM_022445.4(TPK1):​c.489C>T​(p.Tyr163Tyr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,666 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TPK1 NM_022445.4 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: 2.50
• 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)
• Leigh syndrome

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen

ACMG classification

Our verdict: Benign. The variant received -11 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.5).
• BP6: Variant 7-144591435-G-A is Benign according to our data. Variant chr7-144591435-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 540081.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=2.5 with no splicing effect.

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TPK1	NM_022445.4	MANE Select	c.489C>T	p.Tyr163Tyr	synonymous	Exon 7 of 9	NP_071890.2
	TPK1	NM_001350879.1		c.489C>T	p.Tyr163Tyr	synonymous	Exon 7 of 9	NP_001337808.1
	TPK1	NM_001350881.1		c.489C>T	p.Tyr163Tyr	synonymous	Exon 7 of 10	NP_001337810.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TPK1	ENST00000360057.7	TSL:1 MANE Select	c.489C>T	p.Tyr163Tyr	synonymous	Exon 7 of 9	ENSP00000353165.3
	TPK1	ENST00000378098.8	TSL:1	n.*245C>T		non_coding_transcript_exon	Exon 8 of 10	ENSP00000367338.4
	TPK1	ENST00000482940.5	TSL:1	n.*414C>T		non_coding_transcript_exon	Exon 9 of 12	ENSP00000449909.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461666 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 727140

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44710

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86224

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53406

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111868

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

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Benign:1

Feb 01, 2023

CeGaT Center for Human Genetics Tuebingen

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

TPK1: PM2:Supporting, BP4, BP7

Childhood encephalopathy due to thiamine pyrophosphokinase deficiency Benign:1

Mar 18, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.50
CADD	Benign	6.7
DANN	Benign	0.41
PhyloP100		2.5

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		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: rs1554562296; hg19: chr7-144288528;