rs201119006

Positions:

chr20-3213378-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001324236.2(ITPA):c.-154C>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000669 in 1,613,780 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000066 ( 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: 0.727

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 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.18220639).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ITPA	NM_033453.4 linkuse as main transcript	c.184C>T	p.Arg62Cys	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.184C>T	p.Arg62Cys	missense_variant	3/8	1	NM_033453.4	ENSP00000369456.3		Q9BY32-1

Frequencies

GnomAD3 genomes

AF:

0.0000789

AC:

AN:

152134

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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:

0.000132

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000596

AC:

AN:

251482

Hom.:

AF XY:

0.0000515

AC XY:

AN XY:

135920

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.0000578

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:

0.000105

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000657

AC:

AN:

1461646

Hom.:

Cov.:

AF XY:

0.0000688

AC XY:

AN XY:

727140

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000755

Gnomad4 OTH exome

AF:

0.000116

GnomAD4 genome

AF:

0.0000789

AC:

AN:

152134

Hom.:

Cov.:

AF XY:

0.0000673

AC XY:

AN XY:

74298

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000132

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000810

Hom.:

Bravo

AF:

0.0000604

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.0000330

AC:

EpiCase

AF:

0.000273

EpiControl

AF:

0.000178

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

Feb 22, 2023

The c.184C>T (p.R62C) 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 184, causing the arginine (R) at amino acid position 62 to be replaced by a cysteine (C). 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

Oct 03, 2023

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 62 of the ITPA protein (p.Arg62Cys). This variant is present in population databases (rs201119006, gnomAD 0.009%). 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: 579389). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The cysteine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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

0.11

BayesDel_addAF

Benign

-0.19

BayesDel_noAF

Benign

-0.32

CADD

Uncertain

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.92

D;.

Eigen

Benign

-0.27

Eigen_PC

Benign

-0.28

FATHMM_MKL

Benign

0.37

LIST_S2

Uncertain

0.93

D;D

M_CAP

Benign

0.0089

MetaRNN

Benign

0.18

T;T

MetaSVM

Benign

-0.80

MutationAssessor

Pathogenic

3.4

M;.

PrimateAI

Benign

0.41

PROVEAN

Pathogenic

-4.9

D;D

REVEL

Benign

0.12

Sift

Uncertain

0.016

D;D

Sift4G

Uncertain

0.010

D;D

Polyphen

0.064

B;.

Vest4

0.33

MVP

0.47

MPC

0.40

ClinPred

0.89

GERP RS

-0.79

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.57

gMVP

0.55

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

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