rs367746086

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_033453.4(ITPA):​c.66+5C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000161 in 1,613,474 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000092 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

ITPA
NM_033453.4 splice_region, intron

Scores

2
Splicing: ADA: 0.0003433
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -2.63

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 -4 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.55).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ITPANM_033453.4 linkc.66+5C>T splice_region_variant, intron_variant Intron 1 of 7 ENST00000380113.8 NP_258412.1 Q9BY32-1A0A0S2Z3W7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ITPAENST00000380113.8 linkc.66+5C>T splice_region_variant, intron_variant Intron 1 of 7 1 NM_033453.4 ENSP00000369456.3 Q9BY32-1

Frequencies

GnomAD3 genomes
AF:
0.0000921
AC:
14
AN:
151970
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000314
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.0000280
AC:
7
AN:
250310
AF XY:
0.00000738
show subpopulations
Gnomad AFR exome
AF:
0.000432
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000821
AC:
12
AN:
1461504
Hom.:
0
Cov.:
31
AF XY:
0.00000688
AC XY:
5
AN XY:
727074
show subpopulations
African (AFR)
AF:
0.000299
AC:
10
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53316
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111786
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000921
AC:
14
AN:
151970
Hom.:
0
Cov.:
32
AF XY:
0.000108
AC XY:
8
AN XY:
74202
show subpopulations
African (AFR)
AF:
0.000314
AC:
13
AN:
41346
American (AMR)
AF:
0.0000655
AC:
1
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4810
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10584
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67996
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000818
Hom.:
0
Bravo
AF:
0.000106

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Inosine triphosphatase deficiency Uncertain:1
Aug 01, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 1 of the ITPA gene. It does not directly change the encoded amino acid sequence of the ITPA protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs367746086, gnomAD 0.04%). 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: 533424). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. 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
BayesDel_noAF
Benign
-0.55
CADD
Benign
7.3
DANN
Benign
0.93
PhyloP100
-2.6
PromoterAI
-0.048
Neutral
RBP_binding_hub_radar
0.67
RBP_regulation_power_radar
3.2

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.00034
dbscSNV1_RF
Benign
0.18
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: rs367746086; hg19: chr20-3190268; API