chr12-57512849-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_004990.4(MARS1):c.1852C>T(p.Arg618Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000328 in 1,614,092 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: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000036 ( 0 hom. )

Consequence

MARS1
NM_004990.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:2U:4

Conservation

PhyloP100: 3.50

Variant links:

Genes affected

MARS1 (HGNC:6898): (methionyl-tRNA synthetase 1) This gene encodes a member of the class I family of aminoacyl-tRNA synthetases. These enzymes play a critical role in protein biosynthesis by charging tRNAs with their cognate amino acids. The encoded protein is a component of the multi-tRNA synthetase complex and catalyzes the ligation of methionine to tRNA molecules. [provided by RefSeq, Jan 2011]

MARS1 links:

MIR6758 (HGNC:50038): (microRNA 6758) microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts (pri-miRNAs) that can be either protein-coding or non-coding. The primary transcript is cleaved by the Drosha ribonuclease III enzyme to produce an approximately 70-nt stem-loop precursor miRNA (pre-miRNA), which is further cleaved by the cytoplasmic Dicer ribonuclease to generate the mature miRNA and antisense miRNA star (miRNA*) products. The mature miRNA is incorporated into a RNA-induced silencing complex (RISC), which recognizes target mRNAs through imperfect base pairing with the miRNA and most commonly results in translational inhibition or destabilization of the target mRNA. The RefSeq represents the predicted microRNA stem-loop. [provided by RefSeq, Sep 2009]

MIR6758 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.936

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MARS1	NM_004990.4 link	c.1852C>T	p.Arg618Cys	missense_variant	Exon 15 of 21	ENST00000262027.10	NP_004981.2	P56192-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MARS1	ENST00000262027.10 link	c.1852C>T	p.Arg618Cys	missense_variant	Exon 15 of 21	1	NM_004990.4	ENSP00000262027.5		P56192-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152206

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.00

GnomAD3 exomes

AF:

0.00000795

AC:

AN:

251486

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135920

show subpopulations

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:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000356

AC:

AN:

1461886

Hom.:

Cov.:

AF XY:

0.0000468

AC XY:

AN XY:

727244

show subpopulations

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:

0.0000450

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152206

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74354

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.00

Alfa

AF:

0.000108

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:2Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease axonal type 2U

Pathogenic:1

Nov 01, 2013

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Severe early-onset pulmonary alveolar proteinosis due to MARS deficiency

Pathogenic:1

Hadassah Hebrew University Medical Center

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not specified

Uncertain:1

Feb 06, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MARS1 c.1852C>T (p.Arg618Cys) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 3.3e-05 in 1614092 control chromosomes. c.1852C>T has been reported in the literature in trans along with a VUS missense in one infant with interstitial lung and liver disease (Rips_2018) and at a heterozygous state in several individuals affected with CMT2 or CMT, however the carrier parents were reported to be unaffected (Gonzalez_2013, Volodarsky_2021). These report(s) do not provide unequivocal conclusions about association of the variant with MARS1-Related Disorders. Two publications report experimental evidence evaluating an impact on protein function in Yeast, however, none of these studies allows convincing conclusions about the variant effect (Gonzalez_2013, Rips_2018) . The following publications have been ascertained in the context of this evaluation (PMID: 23729695, 29655802, 32376792). ClinVar contains an entry for this variant (Variation ID: 156025). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Charcot-Marie-Tooth disease

Uncertain:1

Molecular Genetics Laboratory, London Health Sciences Centre

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Charcot-Marie-Tooth disease axonal type 2U;C4225400:Severe early-onset pulmonary alveolar proteinosis due to MARS deficiency

Uncertain:1

Jun 06, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 618 of the MARS protein (p.Arg618Cys). This variant is present in population databases (rs587777718, gnomAD 0.002%). This missense change has been observed in individual(s) with autosomal dominant MARS-related conditions and/or autosomal recessive MARS-related conditions (PMID: 23729695, 29655802). ClinVar contains an entry for this variant (Variation ID: 156025). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects MARS function (PMID: 23729695, 29655802). 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. -

not provided

Uncertain:1

Mar 03, 2017

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The R618C variant in the MARS gene has been reported previously in the heterozygous state in a male individual and his maternal uncle, both of whom had late-adult onset of peripheral axonal neuropathy classified as Charcot-Marie-Tooth disease type 2U (CMT2U); however, this variant was also observed in the individual's unaffected mother (Gonzalez et al., 2013). This variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The R618C variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties, and occurs at a position that is conserved across species. In silico analysis predicts this variant is probably damaging to the protein structure/function, and functional studies demonstrated that the R618C variant did not rescue growth of yeast deficient in an ortholog of MARS (Gonzales et al., 2013). However, additional studies are needed to validate the functional effect of this variant in vivo. We interpret R618C as a variant of uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.96

BayesDel_addAF

Pathogenic

0.37

BayesDel_noAF

Pathogenic

0.31

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.94

Eigen

Pathogenic

0.95

Eigen_PC

Pathogenic

0.84

FATHMM_MKL

Uncertain

0.90

LIST_S2

Pathogenic

1.0

M_CAP

Pathogenic

0.58

MetaRNN

Pathogenic

0.94

MetaSVM

Uncertain

0.75

MutationAssessor

Pathogenic

4.8

PrimateAI

Uncertain

0.76

PROVEAN

Pathogenic

-7.7

REVEL

Pathogenic

0.76

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.99

MutPred

0.66

Gain of catalytic residue at L621 (P = 0.0012);

MVP

0.93

MPC

1.0

ClinPred

1.0

GERP RS

5.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.8

Varity_R

0.97

gMVP

0.96

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over