rs765934653

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PP3_ModerateBS1_Supporting

The NM_033453.4(ITPA):​c.363C>A​(p.Ser121Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,613,802 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S121N) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

ITPA
NM_033453.4 missense

Scores

2
9
7

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.878

Publications

2 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: Uncertain_significance. The variant received 1 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.891
BS1
Variant frequency is greater than expected in population amr. GnomAdExome4 allele frequency = 0.0000192 (28/1461598) while in subpopulation AMR AF = 0.000626 (28/44724). AF 95% confidence interval is 0.000444. There are 0 homozygotes in GnomAdExome4. There are 7 alleles in the male GnomAdExome4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_033453.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
ITPA
NM_033453.4
MANE Select
c.363C>Ap.Ser121Arg
missense
Exon 6 of 8NP_258412.1
ITPA
NM_001424408.1
c.363C>Ap.Ser121Arg
missense
Exon 6 of 9NP_001411337.1
ITPA
NM_001424409.1
c.489C>Ap.Ser163Arg
missense
Exon 7 of 9NP_001411338.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
ITPA
ENST00000380113.8
TSL:1 MANE Select
c.363C>Ap.Ser121Arg
missense
Exon 6 of 8ENSP00000369456.3
ITPA
ENST00000455664.6
TSL:1
c.312C>Ap.Ser104Arg
missense
Exon 6 of 8ENSP00000413282.1
ITPA
ENST00000399838.3
TSL:1
c.240C>Ap.Ser80Arg
missense
Exon 4 of 6ENSP00000382732.3

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152204
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000458
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000108
AC:
27
AN:
250130
AF XY:
0.0000517
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000781
Gnomad ASJ exome
AF:
0.00
Gnomad EAS 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:
28
AN:
1461598
Hom.:
0
Cov.:
32
AF XY:
0.00000963
AC XY:
7
AN XY:
727116
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000626
AC:
28
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:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53154
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111986
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.446
Heterozygous variant carriers
0
3
5
8
10
13
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:
0.0000460
AC:
7
AN:
152204
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74358
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41462
American (AMR)
AF:
0.000458
AC:
7
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.532
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000683
Hom.:
0
Bravo
AF:
0.000117
ExAC
AF:
0.0000988
AC:
12

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
Pathogenic
0.83
BayesDel_addAF
Benign
-0.076
T
BayesDel_noAF
Uncertain
0.030
CADD
Benign
21
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.79
D
Eigen
Uncertain
0.28
Eigen_PC
Benign
0.15
FATHMM_MKL
Benign
0.52
D
LIST_S2
Uncertain
0.95
D
M_CAP
Benign
0.014
T
MetaRNN
Pathogenic
0.89
D
MetaSVM
Benign
-0.30
T
MutationAssessor
Uncertain
2.1
M
PhyloP100
0.88
PrimateAI
Uncertain
0.61
T
PROVEAN
Uncertain
-3.3
D
REVEL
Uncertain
0.30
Sift
Benign
0.29
T
Sift4G
Benign
0.27
T
Polyphen
1.0
D
Vest4
0.90
MutPred
0.80
Loss of glycosylation at S121 (P = 0.0715)
MVP
0.60
MPC
1.0
ClinPred
0.35
T
GERP RS
3.9
Varity_R
0.84
gMVP
0.94
Mutation Taster
=52/48
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs765934653; hg19: chr20-3199230; API