Is ABAT p.Leu6= (c.18C>T) pathogenic?

ABAT p.Leu6= (c.18C>T) is classified Likely benign in ABAT (ClinVar, Single submitter, 1 submitter; last evaluated 2025-05-05). Ultra-rare (popmax 0.0165%, mid); Associated with GABA aminotransaminase deficiency.

What condition is associated with ABAT p.Leu6= (c.18C>T)?

ABAT p.Leu6= (c.18C>T) is associated with GABA aminotransaminase deficiency (ClinVar).

How common is ABAT p.Leu6= (c.18C>T) in the general population?

ABAT p.Leu6= (c.18C>T) is ultra-rare (popmax 0.0165%, mid) (gnomAD).

ABAT p.Leu6=

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

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

c.18C>T · rs766349160 · VCV790934

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.0165%, mid)

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 -0.57	GERP -4.9
Overall
CADD	5.443	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0165% Middle Eastern · 1/6,074 alleles

Filtering AF 0.00573% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00526%

Overall 0.00535% 86/1,606,190 alleles · ultra-rare

Ancestry group	Frequency	1 in
Middle Easterngrpmax	0.0165%	6,074
European (non-Finnish)	0.00697%	14,350
East Asian	0.00223%	44,754
African / African-American	0.00134%	74,844
South Asian	0.00112%	89,304

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.Leu6=
Coding: c.18C>T
MANE Select: NM_020686
dbSNP: rs766349160
Type: single nucleotide variant
Location: chr16:8735757 (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-leu6 (accessed [today's date]).

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