Is FIG4 p.Arg766Trp (c.2296C>T) pathogenic?

FIG4 p.Arg766Trp (c.2296C>T) is classified Uncertain significance in FIG4 (ClinVar, Single submitter, 2 submitters; last evaluated 2025-04-14). AlphaMissense: likely benign (0.2143); Very rare (popmax 0.00223%, eas); Associated with Charcot-Marie-Tooth disease type 4.

What condition is associated with FIG4 p.Arg766Trp (c.2296C>T)?

FIG4 p.Arg766Trp (c.2296C>T) is associated with Charcot-Marie-Tooth disease type 4, Yunis-Varon syndrome, Charcot-Marie-Tooth disease type 4J (ClinVar).

How common is FIG4 p.Arg766Trp (c.2296C>T) in the general population?

FIG4 p.Arg766Trp (c.2296C>T) is very rare (popmax 0.00223%, eas) (gnomAD).

What do computational predictors say about FIG4 p.Arg766Trp (c.2296C>T)?

AlphaMissense predicts likely benign (score 0.2143) — an in-silico prediction, not a clinical call.

FIG4 p.Arg766Trp

c.2296C>T · rs552937585 · VCV944958

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 2 submitters

AlphaMissense

likely benign

0.2143 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00223%, eas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Charcot-Marie-Tooth disease type 4

Computational evidence

Protein change
AlphaMissense	0.2143	likely benign
REVEL	0.265	benign-leaning
SaProt	LLR -7.49	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 -0.094	GERP 0.48, phastCons 0.47
Regional constraint	o/e 0.95	unconstrained · MANE · 48 kb · p 0.33 · regional, not allelic
Overall
CADD	25.8	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 0.00223% East Asian · 1/44,878 alleles

Filtering AF 0.000688% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000539%

Overall 0.00105% 17/1,614,014 alleles · very rare exomes 13/1,461,686 · genomes 4/152,328 · joint denominator

Ancestry group	Frequency	1 in
East Asiangrpmax	0.00223%	44,878
South Asian	0.0022%	45,541
European (non-Finnish)	0.00119%	84,289

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: FIG4
Protein: p.Arg766Trp
Coding: c.2296C>T
MANE Select: NM_014845
dbSNP: rs552937585
Type: single nucleotide variant
Location: chr6:109791491 (GRCh38)
Gene constraint: LOEUF 0.966 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 80.65 · 1 PDB
Residue 766: the 'disordered' region

Full FIG4 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Charcot-Marie-Tooth disease type 4 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: Yunis-Varon syndrome Charcot-Marie-Tooth disease type 4J

Similar variants

FIG4 p.Arg766Gln Uncertain significance ★ ⚠ same residue
FIG4 p.Arg766Gly Uncertain significance ★ ⚠ same residue
FIG4 c.1040-1G>A Likely pathogenic ★★ same condition
FIG4 c.1584-1G>T Likely pathogenic ★★ same condition
FIG4 c.1948+1G>A Likely pathogenic ★★ same condition
FIG4 c.1949-10T>G Pathogenic/Likely pathogenic ★★ same condition
FIG4 c.2376+2T>G Likely pathogenic ★★ same condition
FIG4 c.2459+1G>A 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/fig4-p-arg766trp (accessed [today's date]).

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