3-53228076-G-A

Variant names:

• chr3-53228076-G-A
• rs1328734845
• NM_001064.4:c.1553C>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001064.4(TKT):​c.1553C>T​(p.Ala518Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000093 in 1,612,868 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 (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: TKT NM_001064.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.89
• Publications: 0 publications found

Genes affected

TKT (HGNC:11834): (transketolase) This gene encodes a thiamine-dependent enzyme which plays a role in the channeling of excess sugar phosphates to glycolysis in the pentose phosphate pathway. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Apr 2012]

TKT Gene-Disease associations (from GenCC):

• transketolase deficiency

  Inheritance: AR Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.851

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TKT	NM_001064.4	c.1553C>T	p.Ala518Val	missense_variant	Exon 12 of 14	ENST00000462138.6	NP_001055.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TKT	ENST00000462138.6	c.1553C>T	p.Ala518Val	missense_variant	Exon 12 of 14	1	NM_001064.4	ENSP00000417773.1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152250 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000822 AC: 12 AN: 1460618 Hom.: 0 Cov.: 32 AF XY: 0.00000826 AC XY: 6 AN XY: 726628

African (AFR) AF: 0.0000299 AC: 1 AN: 33446

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86196

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53396

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4782

European-Non Finnish (NFE) AF: 0.00000989 AC: 11 AN: 1111952

Other (OTH) AF: 0.00 AC: 0 AN: 60290

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152250 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74380

African (AFR) AF: 0.00 AC: 0 AN: 41482

American (AMR) AF: 0.0000654 AC: 1 AN: 15284

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68034

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000189

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Oct 19, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1553C>T (p.A518V) alteration is located in exon 12 (coding exon 12) of the TKT gene. This alteration results from a C to T substitution at nucleotide position 1553, causing the alanine (A) at amino acid position 518 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.49
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.86	D;D;.;T
Eigen	Pathogenic	0.77
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	.;D;D;D
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.85	D;D;D;D
MetaSVM	Uncertain	0.55	D
MutationAssessor	Uncertain	2.8	M;M;.;.
PhyloP100		9.9
PrimateAI	Uncertain	0.62	T
PROVEAN	Uncertain	-4.0	D;D;D;.
REVEL	Pathogenic	0.69
Sift	Pathogenic	0.0	D;D;D;.
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	D;D;.;.
Vest4		0.74
MutPred		0.79		Gain of catalytic residue at A518 (P = 0.1553);Gain of catalytic residue at A518 (P = 0.1553);.;.;
MVP		0.81
MPC		1.1
ClinPred		0.99	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.86
gMVP		0.94
Mutation Taster		=23/77	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: rs1328734845; hg19: chr3-53262092;