NM_018060.4:c.55C>A

Variant names:

• chr1-220094271-C-A
• rs773732328
• NM_018060.4:c.55C>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_018060.4(IARS2):​c.55C>A​(p.Arg19Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,456,968 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: IARS2 NM_018060.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.62
• Publications: 0 publications found

Genes affected

IARS2 (HGNC:29685): (isoleucyl-tRNA synthetase 2, mitochondrial) Aminoacyl-tRNA synthetases catalyze the aminoacylation of tRNA by their cognate amino acid. Because of their central role in linking amino acids with nucleotide triplets contained in tRNAS, aminoacyl-tRNA synthetases are thought to be among the first proteins that appeared in evolution. Two forms of isoleucine-tRNA synthetase exist, a cytoplasmic form and a mitochondrial form. This gene encodes the mitochondrial isoleucine-tRNA synthetase which belongs to the class-I aminoacyl-tRNA synthetase family. [provided by RefSeq, Dec 2014]

BPNT1 (HGNC:1096): (3'(2'), 5'-bisphosphate nucleotidase 1) BPNT1, also called bisphosphate 3-prime-nucleotidase, or BPntase, is a member of a magnesium-dependent phosphomonoesterase family. Lithium, a major drug used to treat manic depression, acts as an uncompetitive inhibitor of BPntase. The predicted human protein is 92% identical to mouse BPntase. BPntase's physiologic role in nucleotide metabolism may be regulated by inositol signaling pathways. The inhibition of human BPntase may account for lithium-induced nephrotoxicity. [provided by RefSeq, Jul 2008]

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.47).
• BP7: Synonymous conserved (PhyloP=1.62 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_018060.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IARS2	NM_018060.4	MANE Select	c.55C>A	p.Arg19Arg	synonymous	Exon 1 of 23	NP_060530.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IARS2	ENST00000366922.3	TSL:1 MANE Select	c.55C>A	p.Arg19Arg	synonymous	Exon 1 of 23	ENSP00000355889.2	Q9NSE4
	IARS2	ENST00000930953.1		c.55C>A	p.Arg19Arg	synonymous	Exon 1 of 23	ENSP00000601012.1
	IARS2	ENST00000948321.1		c.55C>A	p.Arg19Arg	synonymous	Exon 1 of 23	ENSP00000618380.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000871 AC: 2 AN: 229614 AF XY: 0.00

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000201

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1456968 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 724472

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33258

American (AMR) AF: 0.00 AC: 0 AN: 44352

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25938

East Asian (EAS) AF: 0.00 AC: 0 AN: 39546

South Asian (SAS) AF: 0.00 AC: 0 AN: 85900

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52238

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5680

European-Non Finnish (NFE) AF: 9.01e-7 AC: 1 AN: 1109994

Other (OTH) AF: 0.00 AC: 0 AN: 60062

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.47
CADD	Benign	10
DANN	Benign	0.68
PhyloP100		1.6
PromoterAI		-0.027	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Mutation Taster		=99/1	polymorphism

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

Other links and lift over

dbSNP: rs773732328; hg19: chr1-220267613;