1-173825313-T-C

Variant names:

• chr1-173825313-T-C
• rs199942327
• NM_018122.5:c.84T>C

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_018122.5(DARS2):​c.84T>C​(p.Ser28Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,680 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: DARS2 NM_018122.5 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.908
• Publications: 0 publications found

Genes affected

DARS2 (HGNC:25538): (aspartyl-tRNA synthetase 2, mitochondrial) The protein encoded by this gene belongs to the class-II aminoacyl-tRNA synthetase family. It is a mitochondrial enzyme that specifically aminoacylates aspartyl-tRNA. Mutations in this gene are associated with leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL). [provided by RefSeq, Nov 2009]

DARS2 Gene-Disease associations (from GenCC):

• leukoencephalopathy with brain stem and spinal cord involvement-high lactate syndrome

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P, Orphanet
• mitochondrial disease

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).
• BP6: Variant 1-173825313-T-C is Benign according to our data. Variant chr1-173825313-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 2907445.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-0.908 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DARS2	NM_018122.5	c.84T>C	p.Ser28Ser	synonymous_variant	Exon 1 of 17	ENST00000649689.2	NP_060592.2
DARS2	NM_001365212.1	c.84T>C	p.Ser28Ser	synonymous_variant	Exon 1 of 16		NP_001352141.1
DARS2	NM_001365213.2	c.84T>C	p.Ser28Ser	synonymous_variant	Exon 1 of 14		NP_001352142.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DARS2	ENST00000649689.2	c.84T>C	p.Ser28Ser	synonymous_variant	Exon 1 of 17		NM_018122.5	ENSP00000497569.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152042 Hom.: 0 Cov.: 32

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

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461638 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 727136

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

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53374

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111846

Other (OTH) AF: 0.00 AC: 0 AN: 60390

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.001100), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152042 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74256

African (AFR) AF: 0.00 AC: 0 AN: 41408

American (AMR) AF: 0.00 AC: 0 AN: 15230

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5188

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10584

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68016

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000413 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Benign:1

Jul 07, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.84
CADD	Benign	6.9
DANN	Benign	0.73
PhyloP100		-0.91
PromoterAI		-0.0029	Neutral
Mutation Taster		=100/0	polymorphism

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

Other links and lift over

dbSNP: rs199942327; hg19: chr1-173794451;