Is PCCB p.Pro76Thr (c.226C>A) pathogenic?

PCCB p.Pro76Thr (c.226C>A) is classified Uncertain significance in PCCB (ClinVar, No assertion criteria, 1 submitter; last evaluated 2025-01-16). AlphaMissense: likely benign (0.0842); Absent from gnomAD v4.1; Associated with propionic acidemia.

What condition is associated with PCCB p.Pro76Thr (c.226C>A)?

PCCB p.Pro76Thr (c.226C>A) is associated with propionic acidemia (ClinVar).

How common is PCCB p.Pro76Thr (c.226C>A) in the general population?

PCCB p.Pro76Thr (c.226C>A) is absent from gnomAD v4.1 (gnomAD).

How is Propionic acidemia inherited?

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

What do computational predictors say about PCCB p.Pro76Thr (c.226C>A)?

AlphaMissense predicts likely benign (score 0.0842) — an in-silico prediction, not a clinical call.

PCCB p.Pro76Thr

c.226C>A · VCV4059334

Uncertain significance No assertion criteria

Classification

Uncertain significance

ClinVar

Review

No assertion criteria ☆☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0842 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

1/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

propionic acidemia

Computational evidence

Protein change
AlphaMissense	0.0842	likely benign
REVEL	0.674	pathogenic-leaning
SaProt	LLR -8.23	tolerated
⇒ REVEL calls this damaging; AlphaMissense and SaProt do not.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 4.7	GERP 2.1, phastCons 1
Regional constraint	o/e 1.09	unconstrained · MANE · 80 kb · p 0.017 · regional, not allelic
Overall
CADD	23.3	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: PCCB
Protein: p.Pro76Thr
Coding: c.226C>A
MANE Select: NM_000532
Type: single nucleotide variant
Location: chr3:136255898 (GRCh38)
Gene constraint: LOEUF 0.843 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 93.59 · 24 PDB
Residue 76: the coa carboxyltransferase n-terminal domain; the 'carboxyltransferase' region

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

Disease context

propionic acidemia — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Propionic acidemia (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy, Neonatal
Prevalence: >1 / 1000 (Canada)

Similar variants

PCCB c.1199-1G>A Pathogenic/Likely pathogenic ★★ same condition
PCCB c.1199-2A>G Pathogenic ★★ same condition
PCCB c.1398+1G>C Pathogenic/Likely pathogenic ★★ same condition
PCCB c.1398+1G>T Pathogenic/Likely pathogenic ★★ same condition
PCCB c.1498+2T>C Pathogenic ★★ same condition
PCCB c.1499-1G>C Pathogenic/Likely pathogenic ★★ same condition
PCCB c.183+1G>A Pathogenic/Likely pathogenic ★★ same condition
PCCB c.183+5G>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/pccb-p-pro76thr (accessed [today's date]).

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