rs374178767

chr3-49099761-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_005051.3(QARS1):c.1388G>A(p.Arg463Gln) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000041 in 1,461,682 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: QARS1 NM_005051.3 missense, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.35

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
QARS1	NM_005051.3	c.1388G>A	p.Arg463Gln	missense_variant, splice_region_variant	15/24	ENST00000306125.12
QARS1	NM_001272073.2	c.1355G>A	p.Arg452Gln	missense_variant, splice_region_variant	15/24
QARS1	XM_017006965.3	c.1388G>A	p.Arg463Gln	missense_variant, splice_region_variant	15/23
QARS1	NR_073590.2	n.1363G>A		splice_region_variant, non_coding_transcript_exon_variant	15/24

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
QARS1	ENST00000306125.12	c.1388G>A	p.Arg463Gln	missense_variant, splice_region_variant	15/24	1	NM_005051.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250922 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135616

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: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461682 Hom.: 0 Cov.: 35 AF XY: 0.00000413 AC XY: 3 AN XY: 727150

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: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000403 Hom.: 0

Bravo AF: 0.00000378

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 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

Invitae

Sep 15, 2019

Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with QARS-related disease. This variant is not present in population databases (ExAC no frequency). Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. 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. This sequence change replaces arginine with glutamine at codon 463 of the QARS protein (p.Arg463Gln). The arginine residue is highly conserved and there is a small physicochemical difference between arginine and glutamine. This variant also falls at the last nucleotide of exon 15 of the QARS coding sequence, which is part of the consensus splice site for this exon. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Uncertain	0.077	D
BayesDel_noAF	Benign	-0.13
Cadd	Pathogenic	35
Dann	Pathogenic	1.0
DEOGEN2	Uncertain	0.79	D;.;D
Eigen	Pathogenic	0.70
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Benign	0.044	D
MetaRNN	Uncertain	0.71	D;D;D
MetaSVM	Benign	-0.79	T
MutationAssessor	Benign	2.0	M;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-3.9	D;D;.
REVEL	Uncertain	0.30
Sift	Uncertain	0.0010	D;D;.
Sift4G	Uncertain	0.0050	D;D;D
Polyphen		1.0	D;.;.
Vest4		0.76
MVP		0.58
MPC		1.1
ClinPred		0.99	D
GERP RS		4.4
Varity_R		0.83
gMVP		0.84

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.64		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.64		Position offset: 0

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs374178767; hg19: chr3-49137194;