2-208243460-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 1P and 1B. PP3BS2_Supporting

The NM_005896.4(IDH1):​c.665G>A​(p.Arg222His) variant causes a missense change. The variant allele was found at a frequency of 0.0000136 in 1,613,594 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. R222L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

IDH1
NM_005896.4 missense

Scores

9
8
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.13

Publications

4 publications found
Variant links:
Genes affected
IDH1 (HGNC:5382): (isocitrate dehydrogenase (NADP(+)) 1) Isocitrate dehydrogenases catalyze the oxidative decarboxylation of isocitrate to 2-oxoglutarate. These enzymes belong to two distinct subclasses, one of which utilizes NAD(+) as the electron acceptor and the other NADP(+). Five isocitrate dehydrogenases have been reported: three NAD(+)-dependent isocitrate dehydrogenases, which localize to the mitochondrial matrix, and two NADP(+)-dependent isocitrate dehydrogenases, one of which is mitochondrial and the other predominantly cytosolic. Each NADP(+)-dependent isozyme is a homodimer. The protein encoded by this gene is the NADP(+)-dependent isocitrate dehydrogenase found in the cytoplasm and peroxisomes. It contains the PTS-1 peroxisomal targeting signal sequence. The presence of this enzyme in peroxisomes suggests roles in the regeneration of NADPH for intraperoxisomal reductions, such as the conversion of 2, 4-dienoyl-CoAs to 3-enoyl-CoAs, as well as in peroxisomal reactions that consume 2-oxoglutarate, namely the alpha-hydroxylation of phytanic acid. The cytoplasmic enzyme serves a significant role in cytoplasmic NADPH production. Alternatively spliced transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Sep 2013]
IDH1 Gene-Disease associations (from GenCC):
  • Maffucci syndrome
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.819
BS2
High AC in GnomAdExome4 at 18 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
IDH1NM_005896.4 linkc.665G>A p.Arg222His missense_variant Exon 6 of 10 ENST00000345146.7 NP_005887.2 O75874A0A024R3Y6
IDH1NM_001282386.1 linkc.665G>A p.Arg222His missense_variant Exon 6 of 10 NP_001269315.1 O75874A0A024R3Y6
IDH1NM_001282387.1 linkc.665G>A p.Arg222His missense_variant Exon 6 of 10 NP_001269316.1 O75874A0A024R3Y6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IDH1ENST00000345146.7 linkc.665G>A p.Arg222His missense_variant Exon 6 of 10 1 NM_005896.4 ENSP00000260985.2 O75874
IDH1ENST00000415913.5 linkc.665G>A p.Arg222His missense_variant Exon 6 of 10 1 ENSP00000390265.1 O75874
IDH1ENST00000446179.5 linkc.665G>A p.Arg222His missense_variant Exon 6 of 10 1 ENSP00000410513.1 O75874

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152134
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000197
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
251322
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000123
AC:
18
AN:
1461460
Hom.:
0
Cov.:
30
AF XY:
0.0000151
AC XY:
11
AN XY:
727072
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39682
South Asian (SAS)
AF:
0.0000696
AC:
6
AN:
86246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53356
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00000899
AC:
10
AN:
1111732
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60366
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.442
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000263
AC:
4
AN:
152134
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74312
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41432
American (AMR)
AF:
0.000197
AC:
3
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10598
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.538
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000264
ExAC
AF:
0.00000824
AC:
1

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Jun 22, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R222H variant (also known as c.665G>A), located in coding exon 4 of the IDH1 gene, results from a G to A substitution at nucleotide position 665. The arginine at codon 222 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.26
BayesDel_addAF
Uncertain
0.14
D
BayesDel_noAF
Pathogenic
0.15
CADD
Pathogenic
30
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.82
D;D;D
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.94
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.95
.;.;D
M_CAP
Uncertain
0.15
D
MetaRNN
Pathogenic
0.82
D;D;D
MetaSVM
Pathogenic
0.83
D
MutationAssessor
Pathogenic
3.9
H;H;H
PhyloP100
6.1
PrimateAI
Uncertain
0.74
T
PROVEAN
Uncertain
-4.3
D;D;D
REVEL
Pathogenic
0.74
Sift
Uncertain
0.0010
D;D;D
Sift4G
Uncertain
0.0040
D;D;D
Polyphen
1.0
D;D;D
Vest4
0.47
MutPred
0.69
Loss of methylation at R222 (P = 0.0159);Loss of methylation at R222 (P = 0.0159);Loss of methylation at R222 (P = 0.0159);
MVP
0.97
MPC
0.28
ClinPred
0.98
D
GERP RS
5.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.84
gMVP
0.85
Mutation Taster
=3/97
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.11
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: rs587778401; hg19: chr2-209108184; COSMIC: COSV61624713; API