15-90088606-C-T

Variant names:

• chr15-90088606-C-T
• rs121913503
• NM_002168.4:c.515G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_002168.4(IDH2):​c.515G>A​(p.Arg172Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,894 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 risk factor (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R172S) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: IDH2 NM_002168.4 missense
• Clinical Significance: risk factor no assertion criteria provided O:4
• Conservation: PhyloP100: 7.91
• Publications: 641 publications found

Genes affected

IDH2 (HGNC:5383): (isocitrate dehydrogenase (NADP(+)) 2) 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 mitochondria. It plays a role in intermediary metabolism and energy production. This protein may tightly associate or interact with the pyruvate dehydrogenase complex. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2014]

IDH2 Gene-Disease associations (from GenCC):

• mitochondrial disease

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• d-2-hydroxyglutaric aciduria 2

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• D-2-hydroxyglutaric aciduria

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr15-90088605-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 2691259.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.964

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002168.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IDH2	NM_002168.4	MANE Select	c.515G>A	p.Arg172Lys	missense	Exon 4 of 11	NP_002159.2
	IDH2	NM_001289910.1		c.359G>A	p.Arg120Lys	missense	Exon 4 of 11	NP_001276839.1	P48735-2
	IDH2	NM_001290114.2		c.125G>A	p.Arg42Lys	missense	Exon 2 of 9	NP_001277043.1	B4DSZ6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IDH2	ENST00000330062.8	TSL:1 MANE Select	c.515G>A	p.Arg172Lys	missense	Exon 4 of 11	ENSP00000331897.4	P48735-1
	IDH2	ENST00000864224.1		c.599G>A	p.Arg200Lys	missense	Exon 5 of 12	ENSP00000534283.1
	IDH2	ENST00000864227.1		c.584G>A	p.Arg195Lys	missense	Exon 5 of 12	ENSP00000534286.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461894 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727248

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 31

ClinVar

ClinVar submissions

Significance: risk factor

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
-	-	-	Acute myocardial infarction (1)
-	-	-	Astrocytoma IDH-mutant (1)
-	-	-	IDH-mutant and 1p/19q-codeleted oligodendroglioma (1)
-	-	-	Neoplasm (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.43
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.93	D
Eigen	Uncertain	0.40
Eigen_PC	Benign	0.20
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.36	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	0.82	D
MutationAssessor	Pathogenic	4.2	H
PhyloP100		7.9
PrimateAI	Pathogenic	0.82	D
PROVEAN	Uncertain	-2.9	D
REVEL	Pathogenic	0.73
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.94
MutPred		0.88		Gain of methylation at R172 (P = 0.0071)
MVP		0.82
MPC		1.4
ClinPred		1.0	D
GERP RS		4.1
Varity_R		0.86
gMVP		0.97
Mutation Taster		=8/92	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs121913503; hg19: chr15-90631838; COSMIC: COSV57468734;