KYAT1

Chr 9

kynurenine aminotransferase 1

Also known as: CCBL1, GTK, KAT1, KATI

This enzyme catalyzes the irreversible transamination of L-kynurenine to form kynurenic acid, a broad-spectrum antagonist of ionotropic excitatory amino acid receptors, and also metabolizes cysteine conjugates of halogenated compounds to form reactive metabolites that can cause nephrotoxicity and neurotoxicity. Increased enzyme levels have been associated with schizophrenia, though specific Mendelian diseases caused by KYAT1 mutations have not been established. The gene shows tolerance to loss-of-function variation, suggesting a dominant-negative mechanism if pathogenic mutations occur.

OMIMResearchSummary from RefSeq, UniProt, Mechanism
DNmechanismLOEUF 1.25
Clinical SummaryKYAT1
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.25LOEUF
pLI 0.000
Z-score 0.64
OE 0.86 (0.601.25)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
0.72Z-score
OE missense 0.88 (0.790.98)
233 obs / 265.8 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.86 (0.601.25)
00.351.4
Missense OE0.88 (0.790.98)
00.61.4
Synonymous OE1.04
01.21.6
LoF obs/exp: 20 / 23.3Missense obs/exp: 233 / 265.8Syn Z: -0.30
DN
0.7228th %ile
GOF
0.5857th %ile
LOF
0.2581th %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

KYAT1 · 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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