22-41526289-A-G

Position:

• chr22-41526289-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PM5 PP2 PP3_Moderate

The NM_001098.3(ACO2):​c.1789A>G​(p.Ile597Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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. I597F) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ACO2 NM_001098.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.95

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]

POLR3H (HGNC:30349): (RNA polymerase III subunit H) Enables DNA-directed 5'-3' RNA polymerase activity. Involved in transcription by RNA polymerase III. Located in centrosome and nucleoplasm. Part of RNA polymerase III complex. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr22-41526289-A-T is described in Lovd as [Pathogenic].
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), ACO2. . Gene score misZ 2.9201 (greater than the threshold 3.09). Trascript score misZ 4.3251 (greater than threshold 3.09). GenCC has associacion of gene with infantile cerebellar-retinal degeneration, autosomal recessive optic atrophy, optic atrophy 9.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.929

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ACO2	NM_001098.3	c.1789A>G	p.Ile597Val	missense_variant	15/18	ENST00000216254.9	NP_001089.1
POLR3H	NM_001018050.4	c.*2994T>C		3_prime_UTR_variant	6/6	ENST00000355209.9	NP_001018060.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ACO2	ENST00000216254.9	c.1789A>G	p.Ile597Val	missense_variant	15/18	1	NM_001098.3	ENSP00000216254	P3
POLR3H	ENST00000355209.9	c.*2994T>C		3_prime_UTR_variant	6/6	1	NM_001018050.4	ENSP00000347345	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 25, 2022

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. 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 ACO2 protein function. ClinVar contains an entry for this variant (Variation ID: 1511954). This variant has not been reported in the literature in individuals affected with ACO2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 597 of the ACO2 protein (p.Ile597Val). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.79
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.040
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.62	D;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Uncertain	0.24	D
MetaRNN	Pathogenic	0.93	D;D
MetaSVM	Uncertain	0.63	D
MutationAssessor	Pathogenic	4.8	H;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.77	T
PROVEAN	Benign	-1.0	N;N
REVEL	Uncertain	0.57
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.82
MutPred		0.82		.;Gain of catalytic residue at I622 (P = 0.0925);
MVP		0.89
MPC		1.5
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.73
gMVP		0.82

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr22-41922293;