Is CHD2 p.Pro665Leu (c.1994C>T) pathogenic?

CHD2 p.Pro665Leu (c.1994C>T) is classified Conflicting classifications of pathogenicity in CHD2 (ClinVar, Conflicting submitters, 2 submitters; last evaluated 2025-12-28). AlphaMissense: likely pathogenic (0.9611); Ultra-rare (popmax 0.0165%, mid); Associated with developmental and epileptic encephalopathy 94.

What condition is associated with CHD2 p.Pro665Leu (c.1994C>T)?

CHD2 p.Pro665Leu (c.1994C>T) is associated with developmental and epileptic encephalopathy 94 (ClinVar).

How common is CHD2 p.Pro665Leu (c.1994C>T) in the general population?

CHD2 p.Pro665Leu (c.1994C>T) is ultra-rare (popmax 0.0165%, mid) (gnomAD).

How is Lennox-Gastaut syndrome inherited?

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

What do computational predictors say about CHD2 p.Pro665Leu (c.1994C>T)?

AlphaMissense predicts likely pathogenic (score 0.9611) — an in-silico prediction, not a clinical call.

CHD2 p.Pro665Leu

c.1994C>T · rs773901289 · VCV474375

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 2 submitters

AlphaMissense

likely pathogenic

0.9611 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0165%, mid)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

developmental and epileptic encephalopathy 94

Computational evidence

Protein change
AlphaMissense	0.9611	likely pathogenic
REVEL	0.892	moderately pathogenic-leaning
SaProt	LLR -14.39	damaging
⇒ AlphaMissense, REVEL and SaProt all call this damaging.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 7.7	GERP 2.9, phastCons 1
Regional constraint	o/e 0.44	unconstrained · MANE · 18 kb · p 1e-19 · regional, not allelic
Overall
CADD	33.0	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

Grpmax group 0.0165% Middle Eastern · 1/6,064 alleles

Filtering AF 0.00224% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00199%

Overall 0.00274% 44/1,606,534 alleles · ultra-rare

Ancestry group	Frequency	1 in
Middle Easterngrpmax	0.0165%	6,064
Finnishnot grpmax-eligible	0.0047%	21,279
South Asian	0.00334%	29,911
European (non-Finnish)	0.00306%	32,717
East Asian	0.00223%	44,818

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: CHD2
Protein: p.Pro665Leu
Coding: c.1994C>T
MANE Select: NM_001271
dbSNP: rs773901289
Type: single nucleotide variant
Location: chr15:92956643 (GRCh38)
Gene constraint: LOEUF 0.174 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 60.81
Residue 665: the helicase atp-binding domain; a UniProt-annotated variant site (in dee94); a UniProt-annotated variant site (found in a patient with progressive myoclonus epilepsy; uncertain significance)

Full CHD2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

developmental and epileptic encephalopathy 94 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Lennox-Gastaut syndrome (Orphanet):

Inheritance: Autosomal dominant, Multigenic/multifactorial, Not applicable
Onset: Childhood, Infancy
Prevalence: 1-9 / 1 000 000 (Europe)

Similar variants

CHD2 p.Pro665Gln Uncertain significance ★★ ⚠ same residue
CHD2 p.Pro665Ser Uncertain significance ★★ ⚠ same residue
CHD2 p.Pro665= Benign ★ same residue
CHD2 c.1153+1G>C Pathogenic ★★ same condition
CHD2 c.1809+1G>A Pathogenic/Likely pathogenic ★★ same condition
CHD2 c.294+1G>T Likely pathogenic ★★ same condition
CHD2 c.443+1G>A Pathogenic/Likely pathogenic ★★ same condition
CHD2 c.693-1G>A 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/chd2-p-pro665leu (accessed [today's date]).

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