Is BCO2 p.Thr277Arg (c.830C>G) pathogenic?

BCO2 p.Thr277Arg (c.830C>G) is classified Uncertain significance in BCO2 (ClinVar, Single submitter, 2 submitters; last evaluated 2025-09-10). AlphaMissense: likely benign (0.0769); Rare (popmax 0.131%, mid).

How common is BCO2 p.Thr277Arg (c.830C>G) in the general population?

BCO2 p.Thr277Arg (c.830C>G) is rare (popmax 0.131%, mid) (gnomAD).

What do computational predictors say about BCO2 p.Thr277Arg (c.830C>G)?

AlphaMissense predicts likely benign (score 0.0769) — an in-silico prediction, not a clinical call.

BCO2 p.Thr277Arg

c.830C>G · rs202014484 · VCV2461175

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 2 submitters

AlphaMissense

likely benign

0.0769 · ACMG-weighted

gnomAD v4.1

Rare

rare (popmax 0.131%, mid)

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL no call

Computational evidence

Protein change
AlphaMissense	0.0769	likely benign
REVEL	0.361	indeterminate
SaProt	LLR -6.95	tolerated
⇒ AlphaMissense and SaProt both call this tolerated; REVEL makes no call.
Splicing
SpliceAI	Δ0.27	donor loss · deltas
Pangolin	Δ0.31	loss · gain 0.07 · agrees with SpliceAI · independent
Constraint at this position
Conservation	phyloP -0.002	GERP -2.2
Regional constraint	o/e 0.97	unconstrained · MANE · 42 kb · p 0.37 · regional, not allelic
Overall
CADD	8.282	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

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

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.131% Middle Eastern · 8/6,084 alleles

Filtering AF 0.0654% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0477%

Overall 0.024% 388/1,613,894 alleles · rare exomes 344/1,461,708 · genomes 44/152,186 · joint denominator

Ancestry group	Frequency	1 in
Ashkenazi Jewishnot grpmax-eligible	0.726%	138
Middle Easterngrpmax	0.131%	761
Remaining individualsnot grpmax-eligible	0.072%	1,388
European (non-Finnish)	0.00975%	10,260
Admixed American	0.00667%	14,998
South Asian	0.0011%	91,086

Ashkenazi Jewish shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

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: BCO2
Protein: p.Thr277Arg
Coding: c.830C>G
MANE Select: NM_031938
dbSNP: rs202014484
Type: single nucleotide variant
Location: chr11:112199792 (GRCh38)
Gene constraint: LOEUF 1.047 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 88.41

Full BCO2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

BCO2 p.Arg472Ter Likely benign ★★ same type
BCO2 p.Ala115Val Uncertain significance ★ ⚠ same type
BCO2 p.Ala223Gly Uncertain significance ★ ⚠ same type
BCO2 p.Ala318Val Uncertain significance ★ ⚠ same type
BCO2 p.Ala437Ser Uncertain significance ★ ⚠ same type
BCO2 p.Arg184Trp Uncertain significance ★ ⚠ same type
BCO2 p.Arg253Gln Uncertain significance ★ ⚠ same type
BCO2 p.Arg27Trp 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/bco2-p-thr277arg (accessed [today's date]).

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