2-135920591-G-C

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM2PM5PP2PP3_StrongPP5_Moderate

The NM_001349.4(DARS1):c.821C>G(p.Ala274Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000025 in 1,598,230 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 Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A274V) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 31)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

DARS1
NM_001349.4 missense

Scores

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 9.91

Publications

5 publications found

Variant links:

Genes affected

DARS1 (HGNC:2678): (aspartyl-tRNA synthetase 1) This gene encodes a member of a multienzyme complex that functions in mediating the attachment of amino acids to their cognate tRNAs. The encoded protein ligates L-aspartate to tRNA(Asp). Mutations in this gene have been found in patients showing hypomyelination with brainstem and spinal cord involvement and leg spasticity. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jun 2014]

DARS1 Gene-Disease associations (from GenCC):

hypomyelination with brain stem and spinal cord involvement and leg spasticity
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P

DARS1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr2-135920591-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 50987.Status of the report is no_assertion_criteria_provided, 0 stars.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 10 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: 0.74697 (below the threshold of 3.09). Trascript score misZ: 0.93713 (below the threshold of 3.09). GenCC associations: The gene is linked to hypomyelination with brain stem and spinal cord involvement and leg spasticity.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.983

PP5

Variant 2-135920591-G-C is Pathogenic according to our data. Variant chr2-135920591-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 2988443.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DARS1	NM_001349.4 link	c.821C>G	p.Ala274Gly	missense_variant	Exon 10 of 16	ENST00000264161.9	NP_001340.2
DARS1	NM_001293312.1 link	c.521C>G	p.Ala174Gly	missense_variant	Exon 9 of 15		NP_001280241.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DARS1	ENST00000264161.9 link	c.821C>G	p.Ala274Gly	missense_variant	Exon 10 of 16	1	NM_001349.4	ENSP00000264161.4
DARS1	ENST00000422708.3 link	c.-38C>G		upstream_gene_variant		2		ENSP00000387508.1

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152030

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000725

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

GnomAD4 exome

AF:

6.91e-7

AC:

AN:

1446200

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

719038

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.0000307

AC:

AN:

32548

American (AMR)

AF:

0.00

AC:

AN:

40732

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25418

East Asian (EAS)

AF:

0.00

AC:

AN:

39300

South Asian (SAS)

AF:

0.00

AC:

AN:

82836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52900

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5670

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1107036

Other (OTH)

AF:

0.00

AC:

AN:

59760

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152030

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74266

show subpopulations

African (AFR)

AF:

0.0000725

AC:

AN:

41382

American (AMR)

AF:

0.00

AC:

AN:

15272

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3460

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10584

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68002

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000227

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Pathogenic:1

Jan 31, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt DARS protein function. This missense change has been observed in individual(s) with clinical features of hypomyelination with brain stem and spinal cord involvement and leg spasticity (PMID: 35571067). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 274 of the DARS protein (p.Ala274Gly).

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.90

BayesDel_addAF

Pathogenic

0.17

BayesDel_noAF

Uncertain

0.0

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.81

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.1

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.98

M_CAP

Pathogenic

0.47

MetaRNN

Pathogenic

0.98

MetaSVM

Uncertain

0.45

MutationAssessor

Pathogenic

4.0

PhyloP100

9.9

PrimateAI

Pathogenic

0.84

PROVEAN

Uncertain

-3.7

REVEL

Uncertain

0.60

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.0040

Vest4

0.84

ClinPred

1.0

GERP RS

5.6

PromoterAI

-0.032

Neutral

(source)

Varity_R

0.78

gMVP

0.68

Mutation Taster

=11/89

disease causing

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over