rs754648501

Positions:

• chr3-49096046-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The ENST00000306125.12(QARS1):​c.2311G>A​(p.Asp771Asn) variant causes a missense change. The variant allele was found at a frequency of 0.0000131 in 152,184 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D771A) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 31)
• Consequence: QARS1 ENST00000306125.12 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.03

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
QARS1	NM_005051.3	c.2311G>A	p.Asp771Asn	missense_variant	24/24	ENST00000306125.12	NP_005042.1
QARS1	NM_001272073.2	c.2278G>A	p.Asp760Asn	missense_variant	24/24		NP_001259002.1
QARS1	XM_017006965.3	c.2185G>A	p.Asp729Asn	missense_variant	23/23		XP_016862454.2
QARS1	NR_073590.2	n.2286G>A		non_coding_transcript_exon_variant	24/24

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
QARS1	ENST00000306125.12	c.2311G>A	p.Asp771Asn	missense_variant	24/24	1	NM_005051.3	ENSP00000307567	P1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152184 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000483

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

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250894 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135634

Gnomad AFR exome AF: 0.0000617

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 30

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152184 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74346

Gnomad4 AFR AF: 0.0000483

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: 0.0000189

ExAC AF: 0.00000824 AC: 1

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 30, 2021

This sequence change replaces aspartic acid with asparagine at codon 771 of the QARS protein (p.Asp771Asn). The aspartic acid residue is highly conserved and there is a small physicochemical difference between aspartic acid and asparagine. This variant is present in population databases (rs754648501, ExAC 0.01%). This variant has not been reported in the literature in individuals affected with QARS-related conditions. 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: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.69
BayesDel_addAF	Benign	-0.29	T
BayesDel_noAF	Benign	-0.48
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.37	.;T;.;T
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Benign	0.39	T;D;D;D
M_CAP	Benign	0.013	T
MetaRNN	Uncertain	0.52	D;D;D;D
MetaSVM	Benign	-0.99	T
MutationAssessor	Uncertain	2.3	.;M;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-4.1	D;D;D;.
REVEL	Benign	0.27
Sift	Benign	0.085	T;T;T;.
Sift4G	Uncertain	0.015	D;T;T;T
Polyphen		1.0	.;D;.;.
Vest4		0.72, 0.76, 0.74
MVP		0.62
MPC		1.0
ClinPred		0.98	D
GERP RS		6.1
Varity_R		0.36
gMVP		0.52

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs754648501; hg19: chr3-49133479;