IARS1

Chr 9AR

isoleucyl-tRNA synthetase 1

Also known as: GRIDHH, IARS, ILERS, ILRS, IRS, PRO0785

NCBI Gene: 3376 ENSG00000196305 UniProt: P41252

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]

Primary Disease Associations & Inheritance

Growth retardation, impaired intellectual development, hypotonia, and hepatopathyMIM #617093

Active trials

Pathogenic / LP

453

ClinVar variants

Pubs (1 yr)

1.1

Missense Z

0.77

LOEUF

Clinical Summary— IARS1

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Population Constraint (gnomAD)

Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

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ClinVar Variants

35 Pathogenic / Likely Pathogenic· 255 VUS of 453 total submissions

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GeneReview available — IARS1

Authoritative clinical overview · Recommended first read

Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.

0.77LOEUF

pLI 0.000

Z-score 3.24

OE 0.60 (0.47–0.77)

Tolerant

Typical tolerance to LoF variation

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.

1.13Z-score

OE missense 0.88 (0.82–0.94)

594 obs / 676.9 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.

LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.60 (0.47–0.77)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.88 (0.82–0.94)

0≤0.61.4

Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.1.07

0≤1.21.6

LoF obs/exp: 46 / 76.6Missense obs/exp: 594 / 676.9Syn Z: -0.83

0.5869th %ile

GOF

0.6443th %ile

LOF

0.2971th %ile

The highest-scoring mechanism for this gene is gain-of-function.

GOFprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.