chr7-30609667-C-T

Variant names:

• chr7-30609667-C-T
• rs1554337983
• NM_002047.4:c.818C>T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_002047.4(GARS1):​c.818C>T​(p.Ser273Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,966 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: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GARS1 NM_002047.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.82
• Publications: 0 publications found

Genes affected

GARS1 (HGNC:4162): (glycyl-tRNA synthetase 1) This gene encodes glycyl-tRNA synthetase, one of the aminoacyl-tRNA synthetases that charge tRNAs with their cognate amino acids. The encoded enzyme is an (alpha)2 dimer which belongs to the class II family of tRNA synthetases. It has been shown to be a target of autoantibodies in the human autoimmune diseases, polymyositis or dermatomyositis. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2015]

GARS1 Gene-Disease associations (from GenCC):

• Charcot-Marie-Tooth disease type 2D

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Orphanet
• neuronopathy, distal hereditary motor, type 5A

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Illumina, Laboratory for Molecular Medicine
• spinal muscular atrophy, infantile, James type

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 6 uncertain in NM_002047.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.79

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002047.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GARS1	NM_002047.4	MANE Select	c.818C>T	p.Ser273Phe	missense	Exon 7 of 17	NP_002038.2
	GARS1	NM_001316772.1		c.656C>T	p.Ser219Phe	missense	Exon 7 of 17	NP_001303701.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GARS1	ENST00000389266.8	TSL:1 MANE Select	c.818C>T	p.Ser273Phe	missense	Exon 7 of 17	ENSP00000373918.3
	GARS1	ENST00000675651.1		c.818C>T	p.Ser273Phe	missense	Exon 7 of 17	ENSP00000502513.1
	GARS1	ENST00000675810.1		c.716C>T	p.Ser239Phe	missense	Exon 6 of 16	ENSP00000502743.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460966 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726852

⚠️ 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: 33452

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

East Asian (EAS) AF: 0.00 AC: 0 AN: 39626

South Asian (SAS) AF: 0.00 AC: 0 AN: 86234

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53398

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111288

Other (OTH) AF: 0.00 AC: 0 AN: 60366

⚠️ 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.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Uncertain:1

Apr 18, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. 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: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C15"). ClinVar contains an entry for this variant (Variation ID: 543165). This variant has not been reported in the literature in individuals affected with GARS-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces serine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 273 of the GARS protein (p.Ser273Phe).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.58
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.030
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.65	D
Eigen	Pathogenic	0.72
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.79	D
MetaSVM	Uncertain	0.30	D
PhyloP100		7.8
PrimateAI	Uncertain	0.62	T
PROVEAN	Pathogenic	-4.4	D
REVEL	Uncertain	0.63
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0040	D
Polyphen		0.98	D
Vest4		0.51
MutPred		0.64		Loss of disorder (P = 0.0088)
MVP		0.62
MPC		1.1
ClinPred		1.0	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2
Varity_R		0.62
gMVP		0.71
Mutation Taster		=41/59	disease causing

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: rs1554337983; hg19: chr7-30649283;