FARSB

Chr 2AR

phenylalanyl-tRNA synthetase subunit beta

Also known as: FARSLB, FRSB, HSPC173, NEDBLLA, PheHB, PheRS, RILDBC, RILDBC1

The FARSB gene encodes the regulatory beta subunit of phenylalanyl-tRNA synthetase, which attaches phenylalanine to its corresponding tRNA during protein synthesis. Mutations cause Rajab interstitial lung disease with brain calcifications 1, an autosomal recessive disorder affecting the lungs and central nervous system. The gene shows moderate constraint against loss-of-function variants (LOEUF 0.558).

OMIMResearchSummary from RefSeq, OMIM
DNmechanismARLOEUF 0.561 OMIM phenotype
Clinical SummaryFARSB
Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.33) despite low pLI — interpret in context.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
0.56LOEUF
pLI 0.003
Z-score 3.43
OE 0.33 (0.200.56)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
1.16Z-score
OE missense 0.82 (0.740.91)
259 obs / 317.1 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.33 (0.200.56)
00.351.4
Missense OE0.82 (0.740.91)
00.61.4
Synonymous OE0.91
01.21.6
LoF obs/exp: 10 / 30.4Missense obs/exp: 259 / 317.1Syn Z: 0.72
DN
0.6744th %ile
GOF
0.5464th %ile
LOF
0.3452th %ile

The highest-scoring mechanism for this gene is dominant-negative.

DNprediction 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.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

FARSB · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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