Is ABAT p.Gly320Val (c.959G>T) pathogenic?

ABAT p.Gly320Val (c.959G>T) is classified Uncertain significance in ABAT (ClinVar, Single submitter, 1 submitter; last evaluated 2022-04-20). AlphaMissense: likely pathogenic (0.6463); Absent from gnomAD v4.1; Associated with GABA aminotransaminase deficiency.

What condition is associated with ABAT p.Gly320Val (c.959G>T)?

ABAT p.Gly320Val (c.959G>T) is associated with GABA aminotransaminase deficiency (ClinVar).

How common is ABAT p.Gly320Val (c.959G>T) in the general population?

ABAT p.Gly320Val (c.959G>T) is absent from gnomAD v4.1 (gnomAD).

What do computational predictors say about ABAT p.Gly320Val (c.959G>T)?

AlphaMissense predicts likely pathogenic (score 0.6463) — an in-silico prediction, not a clinical call.

ABAT p.Gly320Val

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

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

c.959G>T · rs1250745987 · VCV2116491

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.6463 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

2/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

GABA aminotransaminase deficiency

Computational evidence

Protein change
AlphaMissense	0.6463	likely pathogenic
REVEL	0.925	moderately pathogenic-leaning
SaProt	LLR -9.33	tolerated
⇒ AlphaMissense and REVEL call this damaging; SaProt does not.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 12	GERP 2.1, phastCons 1
Regional constraint	o/e 0.96	unconstrained · MANE · 46 kb · p 0.32 · regional, not allelic
Overall
CADD	28.1	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: ABAT
Protein: p.Gly320Val
Coding: c.959G>T
MANE Select: NM_020686
dbSNP: rs1250745987
Type: single nucleotide variant
Location: chr16:8774894 (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-gly320val (accessed [today's date]).

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