Is BCAT1 p.Arg122Cys (c.364C>T) pathogenic?

BCAT1 p.Arg122Cys (c.364C>T) is classified Uncertain significance in BCAT1 (ClinVar, Single submitter, 1 submitter; last evaluated 2024-02-05). AlphaMissense: likely benign (0.1275); Very rare (popmax 0.00668%, eas).

How common is BCAT1 p.Arg122Cys (c.364C>T) in the general population?

BCAT1 p.Arg122Cys (c.364C>T) is very rare (popmax 0.00668%, eas) (gnomAD).

What do computational predictors say about BCAT1 p.Arg122Cys (c.364C>T)?

AlphaMissense predicts likely benign (score 0.1275) — an in-silico prediction, not a clinical call.

BCAT1 p.Arg122Cys

c.364C>T · rs754236756 · VCV3133342

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.1275 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00668%, eas)

Missense predictors

1/3 damaging

AlphaMissense, REVEL, SaProt

Computational evidence

Protein change
AlphaMissense	0.1275	likely benign
REVEL	0.077	moderately benign-leaning
SaProt	LLR -12.80	damaging
⇒ SaProt calls this damaging; AlphaMissense and REVEL do not.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 3.7	GERP -1.3, phastCons 0.7
Regional constraint	o/e 0.99	unconstrained · MANE · 131 kb · p 0.77 · regional, not allelic
Overall
CADD	23.2	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

Grpmax group 0.00668% East Asian · 3/44,878 alleles

Filtering AF 0.00177% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000891%

Overall 0.0013% 21/1,612,246 alleles · very rare

Ancestry group	Frequency	1 in
East Asiangrpmax	0.00668%	14,959
African / African-American	0.00401%	24,949
European (non-Finnish)	0.00127%	78,568

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: BCAT1
Protein: p.Arg122Cys
Coding: c.364C>T
MANE Select: NM_005504
dbSNP: rs754236756
Type: single nucleotide variant
Location: chr12:24881327 (GRCh38)
Gene constraint: LOEUF 1.219 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 95.05 · 17 PDB
Residue 122: an α-helix

Full BCAT1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

BCAT1 p.Thr13= Benign ★★ same type
BCAT1 c.7-1070G>A Uncertain significance ★ same type
BCAT1 c.7-1075C>T Uncertain significance ★ same type
BCAT1 c.7-1078C>T Uncertain significance ★ same type
BCAT1 c.7-1082G>T Uncertain significance ★ same type
BCAT1 c.7-1091C>T Uncertain significance ★ same type
BCAT1 p.Ala27Thr Uncertain significance ★ ⚠ same type
BCAT1 p.Ala298Thr Uncertain significance ★ ⚠ same type

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/bcat1-p-arg122cys (accessed [today's date]).

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