Genetic Variant ITPA:p.Ala174Ser (chr20-3223397-G-T) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_033453.4(ITPA):c.520G>T(p.Ala174Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000753 in 1,461,564 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A174T) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

ITPA
NM_033453.4 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -0.124

Publications

0 publications found

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 Gene-Disease associations (from GenCC):

genetic developmental and epileptic encephalopathy
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
developmental and epileptic encephalopathy, 35
Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
inosine triphosphatase deficiency
Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics

ITPA links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.036831886).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ITPA	NM_033453.4 link	c.520G>T	p.Ala174Ser	missense_variant	Exon 8 of 8	ENST00000380113.8	NP_258412.1	Q9BY32-1A0A0S2Z3W7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ITPA	ENST00000380113.8 link	c.520G>T	p.Ala174Ser	missense_variant	Exon 8 of 8	1	NM_033453.4	ENSP00000369456.3		Q9BY32-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000399

AC:

AN:

250730

AF XY:

0.00000738

show subpopulations

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:

0.00000883

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000753

AC:

AN:

1461564

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727074

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44718

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86182

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53238

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00000899

AC:

AN:

1111966

Other (OTH)

AF:

0.00

AC:

AN:

60382

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.466

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.29

BayesDel_noAF

Benign

-0.66

CADD

Benign

0.10

(source)

DANN

Benign

0.76

DEOGEN2

Uncertain

0.45

T;.;.

Eigen

Benign

-1.2

Eigen_PC

Benign

-1.3

FATHMM_MKL

Benign

0.035

LIST_S2

Uncertain

0.96

D;D;D

M_CAP

Benign

0.0037

MetaRNN

Benign

0.037

T;T;T

MetaSVM

Benign

-0.98

MutationAssessor

Benign

0.0050

N;.;.

PhyloP100

-0.12

PrimateAI

Benign

0.23

PROVEAN

Benign

0.67

N;N;N

REVEL

Benign

0.020

Sift

Benign

0.70

T;T;T

Sift4G

Benign

0.65

T;T;T

Polyphen

0.0

B;.;.

Vest4

0.028

MutPred

0.32

Gain of disorder (P = 0.034);.;.;

MVP

0.17

MPC

0.27

ClinPred

0.016

GERP RS

-6.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.29

gMVP

0.31

Mutation Taster

=88/12

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over