rs864309499

chr22-41526319-C-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2 PM5 PP2 PP3_Strong PP5

The NM_001098.3(ACO2):c.1819C>T(p.Arg607Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,460,558 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R607H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: ACO2 NM_001098.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 3.91

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 Pathogenic. Variant got 10 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr22-41526320-G-A is described in Lovd as [Pathogenic].
• PP2: Missense variant where missense usually causes diseases, ACO2
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.971
• PP5: Variant 22-41526319-C-T is Pathogenic according to our data. Variant chr22-41526319-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 218316.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}. Variant chr22-41526319-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACO2	NM_001098.3	c.1819C>T	p.Arg607Cys	missense_variant	15/18	ENST00000216254.9
POLR3H	NM_001018050.4	c.*2964G>A		3_prime_UTR_variant	6/6	ENST00000355209.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACO2	ENST00000216254.9	c.1819C>T	p.Arg607Cys	missense_variant	15/18	1	NM_001098.3	P3
POLR3H	ENST00000355209.9	c.*2964G>A		3_prime_UTR_variant	6/6	1	NM_001018050.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250904 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135640

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: 0.00

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460558 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726590

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Infantile cerebellar-retinal degeneration Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Nov 14, 2013	Likely pathogenicity based on finding it once in trans with another missense variant (P712L) in a 2-year-old male with global delays, bilateral sensorineural hearing loss, hypotonia, ataxia, myclonic jerks, dysmorphisms, small arachnoid cyst. -
Pathogenic, no assertion criteria provided	literature only	OMIM	Oct 19, 2022	- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 10, 2023

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. 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. ClinVar contains an entry for this variant (Variation ID: 218316). This missense change has been observed in individual(s) with clinical features of infantile cerebellar-retinal degeneration (PMID: 26992325). This variant is present in population databases (no rsID available, gnomAD 0.004%). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 607 of the ACO2 protein (p.Arg607Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.24
Cadd	Pathogenic	33
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.90	D;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Uncertain	0.36	D
MutationAssessor	Pathogenic	4.5	H;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-8.0	D;D
REVEL	Uncertain	0.62
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.97
MutPred		0.87		.;Loss of sheet (P = 0.0457);
MVP		0.87
MPC		1.9
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.92
gMVP		0.96

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

LitVar

Other links and lift over

dbSNP: rs864309499; hg19: chr22-41922323; COSMIC: COSV53442569; COSMIC: COSV53442569;