9-32407407-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_002197.3(ACO1):c.244C>T(p.Arg82Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,668 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: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: ACO1 NM_002197.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.23

Genes affected

ACO1 (HGNC:117): (aconitase 1) The protein encoded by this gene is a bifunctional, cytosolic protein that functions as an essential enzyme in the TCA cycle and interacts with mRNA to control the levels of iron inside cells. When cellular iron levels are high, this protein binds to a 4Fe-4S cluster and functions as an aconitase. Aconitases are iron-sulfur proteins that function to catalyze the conversion of citrate to isocitrate. When cellular iron levels are low, the protein binds to iron-responsive elements (IREs), which are stem-loop structures found in the 5' UTR of ferritin mRNA, and in the 3' UTR of transferrin receptor mRNA. When the protein binds to IRE, it results in repression of translation of ferritin mRNA, and inhibition of degradation of the otherwise rapidly degraded transferrin receptor mRNA. The encoded protein has been identified as a moonlighting protein based on its ability to perform mechanistically distinct functions. Alternative splicing results in multiple transcript variants [provided by RefSeq, Jan 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACO1	NM_002197.3	c.244C>T	p.Arg82Cys	missense_variant	3/21	ENST00000309951.8
ACO1	NM_001278352.2	c.244C>T	p.Arg82Cys	missense_variant	4/22
ACO1	NM_001362840.2	c.244C>T	p.Arg82Cys	missense_variant	4/22
ACO1	XM_047423430.1	c.268C>T	p.Arg90Cys	missense_variant	3/21

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACO1	ENST00000309951.8	c.244C>T	p.Arg82Cys	missense_variant	3/21	1	NM_002197.3	P1
ACO1	ENST00000379923.5	c.244C>T	p.Arg82Cys	missense_variant	4/22	5		P1
ACO1	ENST00000541043.5	c.244C>T	p.Arg82Cys	missense_variant	4/22	5		P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251164 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135724

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: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461668 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727118

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

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 30, 2024

The c.244C>T (p.R82C) alteration is located in exon 3 (coding exon 2) of the ACO1 gene. This alteration results from a C to T substitution at nucleotide position 244, causing the arginine (R) at amino acid position 82 to be replaced by a cysteine (C). 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	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.26
Cadd	Pathogenic	33
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D;D;D
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;.;.
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Uncertain	0.38	D
MutationAssessor	Pathogenic	5.1	H;H;H
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.86	D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;D;D
Vest4		0.95
MutPred		0.93		Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);
MVP		0.72
MPC		1.0
ClinPred		1.0	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.83

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs1273311415; hg19: chr9-32407405; COSMIC: COSV100008813;