Is OAT p.Thr109= (c.327C>G) pathogenic?

OAT p.Thr109= (c.327C>G) is classified Likely benign in OAT (ClinVar, Single submitter, 1 submitter; last evaluated 2025-12-19). Very rare (popmax 0.005%, amr); Associated with ornithine aminotransferase deficiency.

What condition is associated with OAT p.Thr109= (c.327C>G)?

OAT p.Thr109= (c.327C>G) is associated with ornithine aminotransferase deficiency (ClinVar).

How common is OAT p.Thr109= (c.327C>G) in the general population?

OAT p.Thr109= (c.327C>G) is very rare (popmax 0.005%, amr) (gnomAD).

How is Gyrate atrophy of choroid and retina inherited?

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

OAT p.Thr109=

c.327C>G · rs1409185490 · VCV1628213

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.005%, amr)

Conditions

ornithine aminotransferase 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 -0.41	GERP -4
Overall
CADD	4.398	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.005% Admixed American · 3/59,994 alleles

Filtering AF 0.00133% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000668%

Overall 0.000744% 12/1,612,678 alleles · very rare exomes 12/1,460,468 · genomes 0/152,210 · joint denominator

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.005%	19,998
European (non-Finnish)	0.000763%	131,083

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: OAT
Protein: p.Thr109=
Coding: c.327C>G
MANE Select: NM_000274
dbSNP: rs1409185490
Type: single nucleotide variant
Location: chr10:124408838 (GRCh38)
Gene constraint: LOEUF 0.968 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 94.29 · 35 PDB

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

Disease context

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

For Gyrate atrophy of choroid and retina (Orphanet):

Inheritance: Autosomal recessive
Onset: Childhood
Prevalence: 1-9 / 100 000 (Finland)

Similar variants

OAT p.Thr109Ile Uncertain significance ⚠ same residue
OAT c.1014+1G>A Likely pathogenic ★★ same condition
OAT c.199+2T>A Likely pathogenic ★★ same condition
OAT c.425-2A>G Pathogenic ★★ same condition
OAT c.520+1G>A Likely pathogenic ★★ same condition
OAT c.648+1G>A Likely pathogenic ★★ same condition
OAT c.772-1G>A Pathogenic/Likely pathogenic ★★ same condition
OAT c.900+1G>A Pathogenic/Likely pathogenic ★★ 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/oat-p-thr109 (accessed [today's date]).

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