Is EEF1A2 p.Pro333= (c.999G>A) pathogenic?

EEF1A2 p.Pro333= (c.999G>A) is classified Likely benign in EEF1A2 (ClinVar, Multiple submitters, 3 submitters; last evaluated 2025-02-16). Ultra-rare (popmax 0.0178%, eas); Associated with developmental and epileptic encephalopathy, 33.

What condition is associated with EEF1A2 p.Pro333= (c.999G>A)?

EEF1A2 p.Pro333= (c.999G>A) is associated with developmental and epileptic encephalopathy, 33 (ClinVar).

How common is EEF1A2 p.Pro333= (c.999G>A) in the general population?

EEF1A2 p.Pro333= (c.999G>A) is ultra-rare (popmax 0.0178%, eas) (gnomAD).

EEF1A2 p.Pro333=

Q: How is Non-specific early-onset epileptic encephalopathy inherited?

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

c.999G>A · rs760721599 · VCV508914

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

gnomAD v4.1

Rare

ultra-rare (popmax 0.0178%, eas)

Conditions

developmental and epileptic encephalopathy, 33

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	<0.2	all four deltas below 0.2 · C>G here scores Δ0.23 · evaluated, not missing
Constraint at this position
Conservation	phyloP -20	GERP -3.8
Overall
CADD	0.046	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0178% East Asian · 8/44,870 alleles

Filtering AF 0.00921% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00722%

Overall 0.0023% 37/1,611,696 alleles · ultra-rare

Ancestry group	Frequency	1 in
East Asiangrpmax	0.0178%	5,609
African / African-American	0.016%	6,245
Remaining individualsnot grpmax-eligible	0.00481%	20,797
Admixed American	0.00167%	59,992
European (non-Finnish)	0.0011%	90,709

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: EEF1A2
Protein: p.Pro333=
Coding: c.999G>A
MANE Select: NM_001958
dbSNP: rs760721599
Type: single nucleotide variant
Location: chr20:63490509 (GRCh38)
Gene constraint: LOEUF 0.314 · pLI 1.00 · ClinGen HI 0/3 (gnomAD)
Structure: AlphaFold pLDDT 88.70 · 2 PDB

Full EEF1A2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

developmental and epileptic encephalopathy, 33 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Non-specific early-onset epileptic encephalopathy (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive, Not applicable
Onset: Infancy, Neonatal

Similar variants

EEF1A2 p.Pro333Arg Uncertain significance ★ ⚠ same residue
EEF1A2 p.Arg266Trp Pathogenic/Likely pathogenic ★★ same condition
EEF1A2 p.Arg423Cys Pathogenic/Likely pathogenic ★★ same condition
EEF1A2 p.Arg69Cys Pathogenic ★★ same condition
EEF1A2 p.Asp91Asn Pathogenic ★★ ⚠ same condition
EEF1A2 p.Asp97Asn Pathogenic/Likely pathogenic ★★ same condition
EEF1A2 p.Glu122Lys Pathogenic/Likely pathogenic ★★ same condition
EEF1A2 p.Glu124Lys 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/eef1a2-p-pro333 (accessed [today's date]).

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