chr1-220094271-C-G

Position:

• chr1-220094271-C-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_018060.4(IARS2):​c.55C>G​(p.Arg19Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000932 in 1,609,152 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: IARS2 NM_018060.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 1.62

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.052237034).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IARS2	NM_018060.4	c.55C>G	p.Arg19Gly	missense_variant	1/23	ENST00000366922.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IARS2	ENST00000366922.3	c.55C>G	p.Arg19Gly	missense_variant	1/23	1	NM_018060.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152184 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: 0.0000147

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.00000436 AC: 1 AN: 229614 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 126682

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000297

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000824 AC: 12 AN: 1456968 Hom.: 0 Cov.: 32 AF XY: 0.00000828 AC XY: 6 AN XY: 724472

Gnomad4 AFR exome AF: 0.0000301

Gnomad4 AMR exome AF: 0.0000225

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: 0.00000721

Gnomad4 OTH exome AF: 0.0000333

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152184 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: 0.0000147

Gnomad4 OTH AF: 0.000478

Bravo AF: 0.0000189

ExAC AF: 0.00000830 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 26, 2021	This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 19 of the IARS2 protein (p.Arg19Gly). This variant is present in population databases (rs773732328, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with IARS2-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The glycine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -
Uncertain significance, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 12, 2021

The c.55C>G (p.R19G) alteration is located in exon 1 (coding exon 1) of the IARS2 gene. This alteration results from a C to G substitution at nucleotide position 55, causing the arginine (R) at amino acid position 19 to be replaced by a glycine (G). 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	Benign	0.058
BayesDel_addAF	Benign	-0.24	T
BayesDel_noAF	Benign	-0.58
CADD	Benign	16
DANN	Benign	0.63
DEOGEN2	Benign	0.016	T
Eigen	Benign	-0.93
Eigen_PC	Benign	-0.88
FATHMM_MKL	Benign	0.033	N
LIST_S2	Benign	0.54	T
M_CAP	Benign	0.032	D
MetaRNN	Benign	0.052	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.0	L
MutationTaster	Benign	1.0	D;N
PrimateAI	Uncertain	0.72	T
Sift4G	Benign	0.55	T
Polyphen		0.0	B
Vest4		0.18
MutPred		0.25		Loss of MoRF binding (P = 0.0042);
MVP		0.22
ClinPred		0.20	T
GERP RS		1.9
Varity_R		0.060
gMVP		0.30

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: rs773732328; hg19: chr1-220267613;