chr20-2660912-A-G

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_006899.5(IDH3B):c.395T>C(p.Leu132Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,461,814 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 (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

IDH3B
NM_006899.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter P:1U:1

Conservation

PhyloP100: 7.06

Publications

5 publications found

Variant links:

Genes affected

IDH3B (HGNC:5385): (isocitrate dehydrogenase (NAD(+)) 3 non-catalytic subunit beta) 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. NAD(+)-dependent isocitrate dehydrogenases catalyze the allosterically regulated rate-limiting step of the tricarboxylic acid cycle. Each isozyme is a heterotetramer that is composed of two alpha subunits, one beta subunit, and one gamma subunit. The protein encoded by this gene is the beta subunit of one isozyme of NAD(+)-dependent isocitrate dehydrogenase. Multiple alternatively spliced transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, Sep 2016]

IDH3B Gene-Disease associations (from GenCC):

retinitis pigmentosa 46
Inheritance: AR Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
IDH3B-related retinopathy
Inheritance: AR Classification: MODERATE Submitted by: ClinGen
retinitis pigmentosa
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

IDH3B links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.983

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IDH3B	NM_006899.5 link	c.395T>C	p.Leu132Pro	missense_variant	Exon 5 of 12	ENST00000380843.9	NP_008830.2	O43837-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IDH3B	ENST00000380843.9 link	c.395T>C	p.Leu132Pro	missense_variant	Exon 5 of 12	1	NM_006899.5	ENSP00000370223.4		O43837-1
IDH3B	ENST00000474315.5 link	c.395T>C	p.Leu132Pro	missense_variant	Exon 5 of 13	1		ENSP00000482773.1		A0A087WZN1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251390

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000342

AC:

AN:

1461814

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727218

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.000347

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1111940

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.465

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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

Cov.:

Alfa

AF:

0.0000431

Hom.:

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Retinitis pigmentosa 46

Pathogenic:1

Oct 01, 2008

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

not provided

Uncertain:1

Dec 09, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 132 of the IDH3B protein (p.Leu132Pro). This variant is present in population databases (rs137853020, gnomAD no frequency). This missense change has been observed in individuals with retinitis pigmentosa (PMID: 18806796). ClinVar contains an entry for this variant (Variation ID: 5506). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt IDH3B protein function with a positive predictive value of 80%. 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

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.39

BayesDel_noAF

Pathogenic

0.32

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.61

D;.;D;D

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.98

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.93

D;D;D;D

M_CAP

Uncertain

0.16

MetaRNN

Pathogenic

0.98

D;D;D;D

MetaSVM

Uncertain

0.58

MutationAssessor

Pathogenic

4.5

.;H;H;.

PhyloP100

7.1

PrimateAI

Pathogenic

0.81

PROVEAN

Pathogenic

-5.7

.;D;D;.

REVEL

Pathogenic

0.82

Sift

Pathogenic

0.0

.;D;D;.

Sift4G

Pathogenic

0.0010

D;D;D;D

Polyphen

1.0

.;D;D;.

Vest4

0.99

MutPred

0.94

Loss of stability (P = 0.0164);Loss of stability (P = 0.0164);Loss of stability (P = 0.0164);Loss of stability (P = 0.0164);

MVP

0.97

MPC

1.5

ClinPred

1.0

GERP RS

5.9

Varity_R

0.99

gMVP

0.97

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over