2-208237128-T-C

Position:

• chr2-208237128-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_005896.4(IDH1):​c.1196A>G​(p.Asp399Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000548 in 1,458,862 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: IDH1 NM_005896.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.63

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IDH1	NM_005896.4	c.1196A>G	p.Asp399Gly	missense_variant	10/10	ENST00000345146.7
IDH1	NM_001282386.1	c.1196A>G	p.Asp399Gly	missense_variant	10/10
IDH1	NM_001282387.1	c.1196A>G	p.Asp399Gly	missense_variant	10/10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IDH1	ENST00000345146.7	c.1196A>G	p.Asp399Gly	missense_variant	10/10	1	NM_005896.4	P1
IDH1	ENST00000415913.5	c.1196A>G	p.Asp399Gly	missense_variant	10/10	1		P1
IDH1	ENST00000446179.5	c.1196A>G	p.Asp399Gly	missense_variant	10/10	1		P1
IDH1	ENST00000484575.1	n.658A>G		non_coding_transcript_exon_variant	3/3	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000200 AC: 5 AN: 250290 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 135244

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000131

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000164

GnomAD4 exome AF: 0.00000548 AC: 8 AN: 1458862 Hom.: 0 Cov.: 27 AF XY: 0.00000413 AC XY: 3 AN XY: 725842

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000581

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome Cov.: 33

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 17, 2024

The c.1196A>G (p.D399G) alteration is located in exon 10 (coding exon 8) of the IDH1 gene. This alteration results from a A to G substitution at nucleotide position 1196, causing the aspartic acid (D) at amino acid position 399 to be replaced by a glycine (G). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D;D;D
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.90	.;.;D
M_CAP	Uncertain	0.20	D
MetaRNN	Uncertain	0.65	D;D;D
MetaSVM	Uncertain	0.51	D
MutationAssessor	Pathogenic	3.0	M;M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-2.8	D;D;D
REVEL	Pathogenic	0.84
Sift	Uncertain	0.025	D;D;D
Sift4G	Uncertain	0.034	D;D;D
Polyphen		0.97	D;D;D
Vest4		0.47
MutPred		0.57		Loss of stability (P = 0.0272);Loss of stability (P = 0.0272);Loss of stability (P = 0.0272);
MVP		0.95
MPC		0.36
ClinPred		0.83	D
GERP RS		5.5
Varity_R		0.80
gMVP		0.91

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs778615461; hg19: chr2-209101852;