rs763741745

Variant names:

• chr3-49098074-A-G
• rs763741745
• NM_005051.3:c.2195T>C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_005051.3(QARS1):​c.2195T>C​(p.Val732Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,890 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: 31)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: QARS1 NM_005051.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.73

Genes affected

QARS1 (HGNC:9751): (glutaminyl-tRNA synthetase 1) 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. In metazoans, 9 aminoacyl-tRNA synthetases specific for glutamine (gln), glutamic acid (glu), and 7 other amino acids are associated within a multienzyme complex. Although present in eukaryotes, glutaminyl-tRNA synthetase (QARS) is absent from many prokaryotes, mitochondria, and chloroplasts, in which Gln-tRNA(Gln) is formed by transamidation of the misacylated Glu-tRNA(Gln). Glutaminyl-tRNA synthetase belongs to the class-I aminoacyl-tRNA synthetase family. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2013]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.826

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
QARS1	NM_005051.3	c.2195T>C	p.Val732Ala	missense_variant	Exon 23 of 24	ENST00000306125.12	NP_005042.1
QARS1	NM_001272073.2	c.2162T>C	p.Val721Ala	missense_variant	Exon 23 of 24		NP_001259002.1
QARS1	XM_017006965.3	c.2151+118T>C		intron_variant	Intron 22 of 22		XP_016862454.2
QARS1	NR_073590.2	n.2170T>C		non_coding_transcript_exon_variant	Exon 23 of 24

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
QARS1	ENST00000306125.12	c.2195T>C	p.Val732Ala	missense_variant	Exon 23 of 24	1	NM_005051.3	ENSP00000307567.6

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251490 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135918

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: 0.00

Gnomad NFE exome AF: 0.0000352

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461890 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727246

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: 0.00000629

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 31

Bravo AF: 0.00000756

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Diffuse cerebral and cerebellar atrophy - intractable seizures - progressive microcephaly syndrome Uncertain:1

May 25, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C15"). ClinVar contains an entry for this variant (Variation ID: 409242). This variant has not been reported in the literature in individuals affected with QARS-related conditions. This variant is present in population databases (rs763741745, gnomAD 0.004%). This sequence change replaces valine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 732 of the QARS protein (p.Val732Ala). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Benign	-0.0057	T
BayesDel_noAF	Benign	-0.14
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Benign	0.19	T;.;T
Eigen	Uncertain	0.39
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.90	D;D;D
M_CAP	Benign	0.025	T
MetaRNN	Pathogenic	0.83	D;D;D
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.1	L;.;.
PrimateAI	Uncertain	0.66	T
PROVEAN	Uncertain	-2.7	D;D;.
REVEL	Benign	0.27
Sift	Benign	0.14	T;T;.
Sift4G	Benign	0.17	T;T;T
Polyphen		0.85	P;.;.
Vest4		0.85
MutPred		0.67		Loss of helix (P = 0.2022);.;.;
MVP		0.40
MPC		1.1
ClinPred		0.67	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.51
gMVP		0.58

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs763741745; hg19: chr3-49135507;