20-3223397-G-A

Variant summary

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

The NM_001424409.1(ITPA):​c.646G>A​(p.Ala216Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000223 in 1,613,756 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. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A216V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

ITPA
NM_001424409.1 missense

Scores

2
16

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

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

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=0.038751036).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001424409.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
ITPA
NM_033453.4
MANE Select
c.520G>Ap.Ala174Thr
missense
Exon 8 of 8NP_258412.1
ITPA
NM_001424409.1
c.646G>Ap.Ala216Thr
missense
Exon 9 of 9NP_001411338.1
ITPA
NM_181493.4
c.469G>Ap.Ala157Thr
missense
Exon 8 of 8NP_852470.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
ITPA
ENST00000380113.8
TSL:1 MANE Select
c.520G>Ap.Ala174Thr
missense
Exon 8 of 8ENSP00000369456.3
ITPA
ENST00000455664.6
TSL:1
c.469G>Ap.Ala157Thr
missense
Exon 8 of 8ENSP00000413282.1
ITPA
ENST00000399838.3
TSL:1
c.397G>Ap.Ala133Thr
missense
Exon 6 of 6ENSP00000382732.3

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152194
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
250730
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.0000617
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000265
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000226
AC:
33
AN:
1461562
Hom.:
0
Cov.:
31
AF XY:
0.0000289
AC XY:
21
AN XY:
727072
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86182
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53238
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000270
AC:
30
AN:
1111964
Other (OTH)
AF:
0.00
AC:
0
AN:
60382
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.440
Heterozygous variant carriers
0
2
4
7
9
11
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
AF:
0.0000197
AC:
3
AN:
152194
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74354
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41460
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000247
AC:
3

ClinVar

ClinVar submissions as Germline
Significance:Uncertain significance
Revision:criteria provided, single submitter
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
1
-
Inosine triphosphatase deficiency (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.091
BayesDel_addAF
Benign
-0.46
T
BayesDel_noAF
Benign
-0.72
CADD
Benign
1.0
DANN
Benign
0.81
DEOGEN2
Uncertain
0.46
T
Eigen
Benign
-1.2
Eigen_PC
Benign
-1.2
FATHMM_MKL
Benign
0.032
N
LIST_S2
Uncertain
0.86
D
M_CAP
Benign
0.0039
T
MetaRNN
Benign
0.039
T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.61
N
PhyloP100
-0.12
PrimateAI
Benign
0.24
T
PROVEAN
Benign
0.65
N
REVEL
Benign
0.021
Sift
Benign
0.53
T
Sift4G
Benign
0.54
T
Polyphen
0.0010
B
Vest4
0.026
MVP
0.17
MPC
0.28
ClinPred
0.019
T
GERP RS
-6.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.17
gMVP
0.34
Mutation Taster
=86/14
polymorphism

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

Other links and lift over

dbSNP: rs747784107; hg19: chr20-3204043; API