chr2-208248388-C-G

Variant names:

• chr2-208248388-C-G
• rs121913500
• NM_005896.4:c.395G>C

Variant summary

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

The NM_005896.4(IDH1):​c.395G>C​(p.Arg132Pro) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R132G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: IDH1 NM_005896.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.17
• Publications: 3767 publications found

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

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 chr2-208248389-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 375891.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.983

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005896.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IDH1	NM_005896.4	MANE Select	c.395G>C	p.Arg132Pro	missense	Exon 4 of 10	NP_005887.2
	IDH1	NM_001282386.1		c.395G>C	p.Arg132Pro	missense	Exon 4 of 10	NP_001269315.1
	IDH1	NM_001282387.1		c.395G>C	p.Arg132Pro	missense	Exon 4 of 10	NP_001269316.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IDH1	ENST00000345146.7	TSL:1 MANE Select	c.395G>C	p.Arg132Pro	missense	Exon 4 of 10	ENSP00000260985.2
	IDH1	ENST00000415913.5	TSL:1	c.395G>C	p.Arg132Pro	missense	Exon 4 of 10	ENSP00000390265.1
	IDH1	ENST00000446179.5	TSL:1	c.395G>C	p.Arg132Pro	missense	Exon 4 of 10	ENSP00000410513.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.37	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.5	H
PhyloP100		6.2
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-6.2	D
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.93		Loss of MoRF binding (P = 0.0352)
MVP		0.99
MPC		0.88
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.99
gMVP		0.99
Mutation Taster		=0/100	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs121913500; hg19: chr2-209113112;