Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong
The NM_002161.6(IARS1):c.3554-3C>T variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,406 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).
IARS1 (HGNC:5330): (isoleucyl-tRNA synthetase 1) Aminoacyl-tRNA synthetases catalyze the aminoacylation of tRNA by their cognate amino acid. Because of their central role in linking amino acids with nucleotide triplets contained in tRNAS, aminoacyl-tRNA synthetases are thought to be among the first proteins that appeared in evolution. Isoleucine-tRNA synthetase belongs to the class-I aminoacyl-tRNA synthetase family and has been identified as a target of autoantibodies in the autoimmune disease polymyositis/dermatomyositis. Alternatively spliced transcript variants have been found. [provided by RefSeq, Nov 2012]
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Jul 20, 2022
This sequence change falls in intron 32 of the IARS gene. It does not directly change the encoded amino acid sequence of the IARS protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs781351325, gnomAD 0.006%). 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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. This variant has not been reported in the literature in individuals affected with IARS-related conditions. -