Is CLPB p.Arg644Leu (c.1931G>T) pathogenic?

CLPB p.Arg644Leu (c.1931G>T) is classified Uncertain significance in CLPB (ClinVar, Single submitter, 1 submitter; last evaluated 2025-09-10). AlphaMissense: likely benign (0.0902); Ultra-rare (popmax 0.0493%, mid); Associated with 3-methylglutaconic aciduria, type VIIB.

What condition is associated with CLPB p.Arg644Leu (c.1931G>T)?

CLPB p.Arg644Leu (c.1931G>T) is associated with 3-methylglutaconic aciduria, type VIIB (ClinVar).

How common is CLPB p.Arg644Leu (c.1931G>T) in the general population?

CLPB p.Arg644Leu (c.1931G>T) is ultra-rare (popmax 0.0493%, mid) (gnomAD).

What do computational predictors say about CLPB p.Arg644Leu (c.1931G>T)?

AlphaMissense predicts likely benign (score 0.0902) — an in-silico prediction, not a clinical call.

CLPB p.Arg644Leu

Q: How is 3-methylglutaconic aciduria-neonatal cataract-neurologic involvement-congenital neutropenia syndrome inherited?

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

c.1931G>T · VCV4705196

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0902 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0493%, mid)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

3-methylglutaconic aciduria, type VIIB

Computational evidence

Protein change
AlphaMissense	0.0902	likely benign
REVEL	0.149	moderately benign-leaning
SaProt	LLR -6.69	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 4.8	GERP 1.8, phastCons 1
Regional constraint	o/e 0.89	unconstrained · MANE · 2,250 bp · p 0.067 · regional, not allelic
Overall
CADD	22.7	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.

⚠ Isoform check: AlphaMissense numbered on a different transcript (AM R674L vs ClinVar R644L) — verify the residue.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0493% Middle Eastern · 3/6,082 alleles

Filtering AF 0.0134% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00716%

Overall 0.000248% 4/1,614,000 alleles · ultra-rare

Ancestry group	Frequency	1 in
Middle Easterngrpmax	0.0493%	2,027
European (non-Finnish)	8.47e-05%	1,180,026

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: CLPB
Protein: p.Arg644Leu
Coding: c.1931G>T
MANE Select: NM_001258392
Type: single nucleotide variant
Location: chr11:72293470 (GRCh38)
Gene constraint: LOEUF 0.643 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 72.52 · 7 PDB

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

Disease context

3-methylglutaconic aciduria, type VIIB — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For 3-methylglutaconic aciduria-neonatal cataract-neurologic involvement-congenital neutropenia syndrome (Orphanet):

Inheritance: Autosomal recessive
Onset: Antenatal, Neonatal

Similar variants

CLPB p.Arg644Cys Uncertain significance ★★ ⚠ same residue
CLPB p.Arg644His Uncertain significance ★ ⚠ same residue
CLPB c.1066+1G>A Pathogenic/Likely pathogenic ★★ same condition
CLPB c.455+1G>A Likely pathogenic ★★ same condition
CLPB c.873+1G>A Pathogenic/Likely pathogenic ★★ same condition
CLPB c.874-2A>G Likely pathogenic ★★ same condition
CLPB p.Arg178Ter Pathogenic ★★ same condition
CLPB p.Arg312Ter 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/clpb-p-arg644leu (accessed [today's date]).

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