22-41515801-G-C

Variant names:

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBS1_SupportingBS2

The NM_001098.3(ACO2):c.719G>C(p.Gly240Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00083 in 1,614,112 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign 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. G240D) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00093 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00082 ( 2 hom. )

Consequence

ACO2
NM_001098.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:14

Conservation

PhyloP100: 9.31

Publications

11 publications found

Variant links:

Genes affected

ACO2 (HGNC:118): (aconitase 2) The protein encoded by this gene belongs to the aconitase/IPM isomerase family. It is an enzyme that catalyzes the interconversion of citrate to isocitrate via cis-aconitate in the second step of the TCA cycle. This protein is encoded in the nucleus and functions in the mitochondrion. It was found to be one of the mitochondrial matrix proteins that are preferentially degraded by the serine protease 15(PRSS15), also known as Lon protease, after oxidative modification. [provided by RefSeq, Jul 2008]

ACO2 Gene-Disease associations (from GenCC):

infantile cerebellar-retinal degeneration
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae)
optic atrophy 9
Inheritance: Unknown, AD, AR Classification: STRONG, MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
autosomal recessive optic atrophy
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACO2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -9 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.03725058).

BS1

Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000932 (142/152332) while in subpopulation NFE AF = 0.00129 (88/68036). AF 95% confidence interval is 0.00107. There are 0 homozygotes in GnomAd4. There are 75 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High Homozygotes in GnomAdExome4 at 2 Unknown,AR,AD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ACO2	NM_001098.3 link	c.719G>C	p.Gly240Ala	missense_variant	Exon 6 of 18	ENST00000216254.9	NP_001089.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ACO2	ENST00000216254.9 link	c.719G>C	p.Gly240Ala	missense_variant	Exon 6 of 18	1	NM_001098.3	ENSP00000216254.4

Frequencies

GnomAD3 genomes

AF:

0.000933

AC:

142

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

Gnomad AMI

AF:

0.0395

Gnomad AMR

AF:

0.000392

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.000377

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00129

Gnomad OTH

AF:

0.00191

GnomAD2 exomes

AF:

0.000585

AC:

147

AN:

251480

AF XY:

0.000581

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.000173

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000139

Gnomad NFE exome

AF:

0.00118

Gnomad OTH exome

AF:

0.000326

GnomAD4 exome

AF:

0.000820

AC:

1198

AN:

1461780

Hom.:

Cov.:

AF XY:

0.000831

AC XY:

604

AN XY:

727198

show subpopulations

African (AFR)

AF:

0.000119

AC:

AN:

33476

American (AMR)

AF:

0.000112

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:

0.0000348

AC:

AN:

86252

European-Finnish (FIN)

AF:

0.000225

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5682

European-Non Finnish (NFE)

AF:

0.00103

AC:

1148

AN:

1112012

Other (OTH)

AF:

0.000431

AC:

AN:

60382

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.487

Heterozygous variant carriers

155

232

310

387

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

114

152

190

<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:

0.000932

AC:

142

AN:

152332

Hom.:

Cov.:

AF XY:

0.00101

AC XY:

AN XY:

74476

show subpopulations

African (AFR)

AF:

0.0000962

AC:

AN:

41570

American (AMR)

AF:

0.000392

AC:

AN:

15312

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5180

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.000377

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00129

AC:

AN:

68036

Other (OTH)

AF:

0.00189

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.510

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.00108

Hom.:

Bravo

AF:

0.00109

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00130

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.00163

AC:

ExAC

AF:

0.000511

AC:

EpiCase

AF:

0.00109

EpiControl

AF:

0.000771

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:14

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:7

Jan 19, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 240 of the ACO2 protein (p.Gly240Ala). This variant is present in population databases (rs141878785, gnomAD 0.1%), and has an allele count higher than expected for a pathogenic variant. This missense change has been observed in individual(s) with optic atrophy (PMID: 34056600). ClinVar contains an entry for this variant (Variation ID: 214018). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt ACO2 protein function with a negative 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.

Jan 30, 2023

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Reported as a homozygous variant of uncertain significance in an individual with complex ataxia, pyramidal syndrome, and cerebellar atrophy; this individual did not have optic atrophy or retinal degeneration and had normal mitochondrial aconitase activity in fibroblasts (Marelli et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 34056600, 32483926, 27528516, 30552426, 34354088, 32519519, 36294366)

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

Sep 01, 2023

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

ACO2: PM2, PM3:Supporting, PM5:Supporting, PP3

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

Feb 03, 2023

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

Retinal dystrophy

Uncertain:2

Jan 01, 2023

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Apr 21, 2018

Blueprint Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Inborn genetic diseases

Uncertain:1

Sep 23, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.719G>C (p.G240A) alteration is located in exon 6 (coding exon 6) of the ACO2 gene. This alteration results from a G to C substitution at nucleotide position 719, causing the glycine (G) at amino acid position 240 to be replaced by an alanine (A). The in silico prediction for the p.G240A alteration is inconclusive. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

Mitochondrial disease

Uncertain:1

Aug 16, 2022

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:research

Infantile cerebellar-retinal degeneration;C4225384:Optic atrophy 9

Uncertain:1

Jan 03, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Optic atrophy 9

Uncertain:1

Dec 17, 2018

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was classified as: Uncertain significance. The available evidence favors the pathogenic nature of this variant, however the currently available data is insufficient to conclusively support its pathogenic nature. Thus this variant is classified as Uncertain significance - favor pathogenic. The following ACMG criteria were applied in classifying this variant: PP2,PP3.

Infantile cerebellar-retinal degeneration

Uncertain:1

Sep 28, 2018

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868].

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.23

BayesDel_addAF

Benign

-0.055

BayesDel_noAF

Uncertain

0.11

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.59

D;.

Eigen

Uncertain

0.60

Eigen_PC

Uncertain

0.61

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.91

D;D

M_CAP

Uncertain

0.094

MetaRNN

Benign

0.037

T;T

MetaSVM

Uncertain

0.11

MutationAssessor

Uncertain

2.6

M;.

PhyloP100

9.3

PrimateAI

Uncertain

0.73

PROVEAN

Pathogenic

-5.4

D;D

REVEL

Pathogenic

0.66

Sift

Uncertain

0.0010

D;D

Sift4G

Uncertain

0.035

D;D

Vest4

0.72

ClinPred

0.28

GERP RS

5.8

Varity_R

0.87

gMVP

0.85

Mutation Taster

=11/89

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.14

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

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over