chr22-41499765-C-T

Variant names:

• chr22-41499765-C-T
• rs1057518832
• NM_001098.3:c.76C>T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP5 BP4 BP7

The NM_001098.3(ACO2):​c.76C>T​(p.Leu26Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,720 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: ACO2 NM_001098.3 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2
• Conservation: PhyloP100: 0.778

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-41499765-C-T is Pathogenic according to our data. Variant chr22-41499765-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 374008.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Pathogenic=1}.
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.3). . Strength limited to SUPPORTING due to the PP5.
• BP7: Synonymous conserved (PhyloP=0.778 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ACO2	NM_001098.3	c.76C>T	p.Leu26Leu	synonymous_variant	Exon 2 of 18	ENST00000216254.9	NP_001089.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ACO2	ENST00000216254.9	c.76C>T	p.Leu26Leu	synonymous_variant	Exon 2 of 18	1	NM_001098.3	ENSP00000216254.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152216 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461504 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727054

Gnomad4 AFR exome AF: 0.00

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: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152216 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74362

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Acute intermittent porphyria Pathogenic:1

-

Neuberg Centre For Genomic Medicine, NCGM

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The missense variant p.R26C in HMBS (NM_000190.4) has been reported previously in multiple affected patients (Dragneva S et al, Méndez M et al). Functional studies reveal a damaging effect (Mustajoki S et al, Ulbrichova D et al). The variant has been submitted to ClinVar as Pathogenic. The missense variant c.76C>T (p.R26C) in HMBS (NM_000190.4) is observed in 1/34592 (0.0029%) alleles from individuals of Latino background in the gnomAD dataset (Exome Aggregation Consortium et al., 2016), but was not seen in the homozygous state. For these reasons, this variant has been classified as Pathogenic. -

Optic atrophy 9 Uncertain:1

Jan 01, 2016

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. This variant was inherited from a parent. -

Neurodegeneration;C0557874:Global developmental delay;C1850456:Progressive microcephaly;C3805839:Central hypoventilation;C4551584:Brain atrophy Uncertain:1

Oct 06, 2015

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.30
CADD	Benign	9.4
DANN	Benign	0.72

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: rs1057518832; hg19: chr22-41895769;