Is ABAT p.Leu131= (c.393C>T) pathogenic?

ABAT p.Leu131= (c.393C>T) is classified Likely benign in ABAT (ClinVar, Single submitter, 1 submitter; last evaluated 2025-11-18). Ultra-rare (popmax 0.0334%, nfe); Associated with GABA aminotransaminase deficiency.

What condition is associated with ABAT p.Leu131= (c.393C>T)?

ABAT p.Leu131= (c.393C>T) is associated with GABA aminotransaminase deficiency (ClinVar).

How common is ABAT p.Leu131= (c.393C>T) in the general population?

ABAT p.Leu131= (c.393C>T) is ultra-rare (popmax 0.0334%, nfe) (gnomAD).

ABAT p.Leu131=

Q: How is Gamma-aminobutyric acid transaminase deficiency inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

c.393C>T · rs139142171 · VCV1550506

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.0334%, nfe)

Conditions

GABA aminotransaminase deficiency

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -5.1	GERP -4.2
Overall
CADD	0.196	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0334% European (non-Finnish) · 394/1,180,016 alleles

Filtering AF 0.0306% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0295%

Overall 0.0252% 406/1,613,592 alleles · ultra-rare

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.0334%	2,995
Remaining individualsnot grpmax-eligible	0.0128%	7,810
African / African-American	0.00401%	24,939
Admixed American	0.00167%	59,938

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: ABAT
Protein: p.Leu131=
Coding: c.393C>T
MANE Select: NM_020686
dbSNP: rs139142171
Type: single nucleotide variant
Location: chr16:8764095 (GRCh38)
Gene constraint: LOEUF 0.871 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 93.91

Full ABAT gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

GABA aminotransaminase deficiency — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Gamma-aminobutyric acid transaminase deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy, Neonatal

Similar variants

ABAT c.168+1G>A Pathogenic ★★ same condition
ABAT p.Arg92Gln Pathogenic/Likely pathogenic ★★ ⚠ same condition
ABAT p.Gln8Ter Pathogenic/Likely pathogenic ★★ same condition
ABAT p.Leu211Phe Pathogenic/Likely pathogenic ★★ same condition
ABAT p.Tyr376Ter Pathogenic/Likely pathogenic ★★ same condition
ABAT c.1381+6G>T Uncertain significance ★★ same condition
ABAT p.Ala162Thr Uncertain significance ★★ ⚠ same condition
ABAT p.Ala226Val Uncertain significance ★★ ⚠ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/abat-p-leu131 (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown