Is ABAT p.Arg436Ter (c.1306C>T) pathogenic?

ABAT p.Arg436Ter (c.1306C>T) is classified Conflicting classifications of pathogenicity in ABAT (ClinVar, Conflicting submitters, 3 submitters; last evaluated 2024-05-09). Very rare (popmax 0.00133%, afr); Associated with GABA aminotransaminase deficiency.

What condition is associated with ABAT p.Arg436Ter (c.1306C>T)?

ABAT p.Arg436Ter (c.1306C>T) is associated with GABA aminotransaminase deficiency (ClinVar).

How common is ABAT p.Arg436Ter (c.1306C>T) in the general population?

ABAT p.Arg436Ter (c.1306C>T) is very rare (popmax 0.00133%, afr) (gnomAD).

ABAT p.Arg436Ter

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

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

c.1306C>T · rs1389255922 · VCV2663056

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 3 submitters

Consequence

nonsense (stop-gain)

predicted LoF

gnomAD v4.1

Rare

very rare (popmax 0.00133%, afr)

Conditions

GABA aminotransaminase deficiency

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	nonsense (stop-gain)	predicted loss-of-function
NMD	predicted	premature termination codon in exon 15 of 16
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 1	GERP 0.61, phastCons 0.73
Overall
CADD	41.0	PHRED · no single calibrated threshold — expert panels disagree

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00133% African / African-American · 1/74,908 alleles

Filtering AF 0.000124% ClinGen BA1/BS1 input FAF95, joint · FAF99 9e-05%

Overall 0.000434% 7/1,614,020 alleles · very rare

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.00133%	74,908
South Asian	0.0011%	91,076
European (non-Finnish)	0.000424%	236,008

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.Arg436Ter
Coding: c.1306C>T
MANE Select: NM_020686
dbSNP: rs1389255922
Type: single nucleotide variant
Location: chr16:8779515 (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 p.Arg436Gln Uncertain significance ★ ⚠ same residue
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

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-arg436ter (accessed [today's date]).

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