BAAT

Chr 9AR

bile acid-CoA:amino acid N-acyltransferase

Also known as: BACAT, BACD1, BAT, FHCA3, HCHO

BAAT encodes a liver enzyme that conjugates bile acids with glycine or taurine, which is essential for bile acid function as detergents that facilitate lipid and fat-soluble vitamin absorption in the intestine. Biallelic mutations cause familial hypercholanemia, characterized by elevated bile acid levels. This follows autosomal recessive inheritance and the gene is highly tolerant to loss-of-function variants (low constraint).

OMIMResearchSummary from RefSeq, OMIM, UniProt
DNmechanismARLOEUF 1.391 OMIM phenotype
Clinical SummaryBAAT
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Gene-Disease Validity (ClinGen)
bile acid CoA:amino acid N-acyltransferase deficiency · ARModerate

Moderate evidence — consider for supplementary testing

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
1.39LOEUF
pLI 0.000
Z-score 0.50
OE 0.86 (0.551.39)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
0.01Z-score
OE missense 1.00 (0.891.11)
221 obs / 221.6 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.86 (0.551.39)
00.351.4
Missense OE1.00 (0.891.11)
00.61.4
Synonymous OE1.08
01.21.6
LoF obs/exp: 12 / 14.0Missense obs/exp: 221 / 221.6Syn Z: -0.55
DN
0.6840th %ile
GOF
0.4381th %ile
LOF
0.2678th %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

BAAT · 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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