rs142979373

Positions:

chr20-3213322-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001324236.2(ITPA):c.-210C>T variant causes a 5 prime UTR premature start codon gain change. The variant allele was found at a frequency of 0.0000235 in 1,613,952 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

ITPA
NM_001324236.2 5_prime_UTR_premature_start_codon_gain

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 6.25

Variant links:

Genes affected

ITPA (HGNC:6176): (inosine triphosphatase) This gene encodes an inosine triphosphate pyrophosphohydrolase. The encoded protein hydrolyzes inosine triphosphate and deoxyinosine triphosphate to the monophosphate nucleotide and diphosphate. This protein, which is a member of the HAM1 NTPase protein family, is found in the cytoplasm and acts as a homodimer. Defects in the encoded protein can result in inosine triphosphate pyrophosphorylase deficiency which causes an accumulation of ITP in red blood cells. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Jun 2012]

ITPA links:

ITPA (HGNC:):

ITPA links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ITPA	NM_033453.4 linkuse as main transcript	c.128C>T	p.Pro43Leu	missense_variant	3/8	ENST00000380113.8	NP_258412.1	Q9BY32-1A0A0S2Z3W7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ITPA	ENST00000380113.8 linkuse as main transcript	c.128C>T	p.Pro43Leu	missense_variant	3/8	1	NM_033453.4	ENSP00000369456.3		Q9BY32-1

Frequencies

GnomAD3 genomes

AF:

0.0000658

AC:

AN:

152074

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000217

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000477

AC:

AN:

251494

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135922

show subpopulations

Gnomad AFR exome

AF:

0.000369

Gnomad AMR exome

AF:

0.000173

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000192

AC:

AN:

1461760

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

727184

show subpopulations

Gnomad4 AFR exome

AF:

0.000388

Gnomad4 AMR exome

AF:

0.000134

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000450

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000657

AC:

AN:

152192

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74380

show subpopulations

Gnomad4 AFR

AF:

0.000217

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000986

Hom.:

Bravo

AF:

0.0000869

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000494

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 29, 2023

The c.128C>T (p.P43L) alteration is located in exon 3 (coding exon 3) of the ITPA gene. This alteration results from a C to T substitution at nucleotide position 128, causing the proline (P) at amino acid position 43 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Inosine triphosphatase deficiency

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 07, 2023

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 43 of the ITPA protein (p.Pro43Leu). This variant is present in population databases (rs142979373, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with ITPA-related conditions. ClinVar contains an entry for this variant (Variation ID: 574417). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.30

BayesDel_addAF

Benign

-0.18

BayesDel_noAF

Benign

-0.17

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.89

D;.

Eigen

Uncertain

0.52

Eigen_PC

Uncertain

0.51

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.97

D;D

M_CAP

Benign

0.021

MetaRNN

Uncertain

0.70

D;D

MetaSVM

Uncertain

-0.077

MutationAssessor

Uncertain

2.7

M;.

PrimateAI

Uncertain

0.76

PROVEAN

Pathogenic

-9.1

D;D

REVEL

Benign

0.27

Sift

Uncertain

0.025

D;D

Sift4G

Benign

0.063

T;T

Polyphen

0.43

B;.

Vest4

0.81

MVP

0.71

MPC

0.64

ClinPred

0.92

GERP RS

4.6

RBP_binding_hub_radar

0.97

RBP_regulation_power_radar

2.1

Varity_R

0.72

gMVP

0.75

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.090

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over