Is CRYBB3 p.Glu177Asp (c.531G>T) pathogenic?

CRYBB3 p.Glu177Asp (c.531G>T) is classified Uncertain significance in CRYBB3 (ClinVar, Multiple submitters, 3 submitters; last evaluated 2024-11-12). AlphaMissense: likely benign (0.0887); Ultra-rare (popmax 0.033%, mid); Associated with cataract 22 multiple types.

What condition is associated with CRYBB3 p.Glu177Asp (c.531G>T)?

CRYBB3 p.Glu177Asp (c.531G>T) is associated with cataract 22 multiple types (ClinVar).

How common is CRYBB3 p.Glu177Asp (c.531G>T) in the general population?

CRYBB3 p.Glu177Asp (c.531G>T) is ultra-rare (popmax 0.033%, mid) (gnomAD).

How is Early onset non-syndromic cataract inherited?

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

What do computational predictors say about CRYBB3 p.Glu177Asp (c.531G>T)?

AlphaMissense predicts likely benign (score 0.0887) — an in-silico prediction, not a clinical call.

CRYBB3 p.Glu177Asp

c.531G>T · rs201027853 · VCV900831

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

AlphaMissense

likely benign

0.0887 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.033%, mid)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

cataract 22 multiple types

Computational evidence

Protein change
AlphaMissense	0.0887	likely benign
REVEL	0.181	moderately benign-leaning
SaProt	LLR -6.53	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 -0.046	GERP -2.2, phastCons 0.27
Regional constraint	o/e 1.00	unconstrained · MANE · 5,812 bp · p 0.93 · regional, not allelic
Overall
CADD	12.35	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 0.033% Middle Eastern · 2/6,060 alleles

Filtering AF 0.0139% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0133%

Overall 0.0125% 202/1,613,278 alleles · ultra-rare

Ancestry group	Frequency	1 in
Middle Easterngrpmax	0.033%	3,030
European (non-Finnish)	0.0159%	6,308
Remaining individualsnot grpmax-eligible	0.0128%	7,811
Admixed American	0.005%	20,010
South Asian	0.0022%	45,535

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: CRYBB3
Protein: p.Glu177Asp
Coding: c.531G>T
MANE Select: NM_004076
dbSNP: rs201027853
Type: single nucleotide variant
Location: chr22:25207107 (GRCh38)
Gene constraint: LOEUF 1.588 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 87.52 · 1 PDB
Residue 177: a β-strand; the beta/gamma crystallin 'greek key' 4 domain

Full CRYBB3 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

cataract 22 multiple types — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Early onset non-syndromic cataract (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive, X-linked recessive
Onset: Infancy, Neonatal

Similar variants

CRYBB3 p.Arg127Cys Uncertain significance ★★ ⚠ same condition
CRYBB3 p.Arg127His Uncertain significance ★★ ⚠ same condition
CRYBB3 p.Arg152Cys Uncertain significance ★★ ⚠ same condition
CRYBB3 p.Arg169Cys Uncertain significance ★★ ⚠ same condition
CRYBB3 p.Arg179His Uncertain significance ★★ ⚠ same condition
CRYBB3 p.Arg207His Uncertain significance ★★ ⚠ same condition
CRYBB3 p.Arg75Cys Uncertain significance ★★ ⚠ same condition
CRYBB3 p.Arg75His Uncertain significance ★★ ⚠ 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/crybb3-p-glu177asp (accessed [today's date]).

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