5-140691214-C-T

Variant names:

• chr5-140691214-C-T
• rs1554109203
• NM_002109.6:c.90+1G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_002109.6(HARS1):​c.90+1G>A variant causes a splice donor, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000691 in 1,446,450 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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: 6.9e-7 (0 hom.)
• Consequence: HARS1 NM_002109.6 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.80
• Publications: 0 publications found

Genes affected

HARS1 (HGNC:4816): (histidyl-tRNA synthetase 1) Aminoacyl-tRNA synthetases are a class of enzymes that charge tRNAs with their cognate amino acids. The protein encoded by this gene is a cytoplasmic enzyme which belongs to the class II family of aminoacyl-tRNA synthetases. The enzyme is responsible for the synthesis of histidyl-transfer RNA, which is essential for the incorporation of histidine into proteins. The gene is located in a head-to-head orientation with HARSL on chromosome five, where the homologous genes share a bidirectional promoter. The gene product is a frequent target of autoantibodies in the human autoimmune disease polymyositis/dermatomyositis. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2012]

HARS2 (HGNC:4817): (histidyl-tRNA synthetase 2, mitochondrial) Aminoacyl-tRNA synthetases are a class of enzymes that charge tRNAs with their cognate amino acids. The protein encoded by this gene is an enzyme belonging to the class II family of aminoacyl-tRNA synthetases. Functioning in the synthesis of histidyl-transfer RNA, the enzyme plays an accessory role in the regulation of protein biosynthesis. The gene is located in a head-to-head orientation with HARS on chromosome five, where the homologous genes likely share a bidirectional promoter. Mutations in this gene are associated with the pathogenesis of Perrault syndrome, which involves ovarian dysgenesis and sensorineural hearing loss. Alternative splicing results in multiple transcript variants of this gene. [provided by RefSeq, Jul 2013]

HARS2 Gene-Disease associations (from GenCC):

• Perrault syndrome 2

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), PanelApp Australia
• Perrault syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.101960786 fraction of the gene.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002109.6. 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
	HARS1	NM_002109.6	MANE Select	c.90+1G>A		splice_donor intron	N/A	NP_002100.2
	HARS1	NM_001258041.3		c.90+1G>A		splice_donor intron	N/A	NP_001244970.1
	HARS1	NM_001289094.2		c.3+88G>A		intron	N/A	NP_001276023.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HARS1	ENST00000504156.7	TSL:1 MANE Select	c.90+1G>A		splice_donor intron	N/A	ENSP00000425634.1
	HARS1	ENST00000457527.6	TSL:1	c.90+1G>A		splice_donor intron	N/A	ENSP00000387893.2
	HARS1	ENST00000507746.7	TSL:5	c.90+1G>A		splice_donor intron	N/A	ENSP00000425889.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.91e-7 AC: 1 AN: 1446450 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 719690

⚠️ 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: 33276

American (AMR) AF: 0.00 AC: 0 AN: 44002

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25654

East Asian (EAS) AF: 0.00 AC: 0 AN: 39642

South Asian (SAS) AF: 0.00 AC: 0 AN: 85410

European-Finnish (FIN) AF: 0.0000213 AC: 1 AN: 47000

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5728

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1105776

Other (OTH) AF: 0.00 AC: 0 AN: 59962

⚠️ 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.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Usher syndrome type 3B Uncertain:1

Feb 25, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 1 of the HARS gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), however the current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in HARS cause disease. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with HARS-related conditions. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	29
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Uncertain	0.92	D
PhyloP100		1.8
GERP RS		5.5
PromoterAI		0.033	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=4/96	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.37		Position offset: 16
DS_DL_spliceai		0.99		Position offset: 1

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

Other links and lift over

dbSNP: rs1554109203; hg19: chr5-140070799;