Is CHIA p.Val440Met (c.1318G>A) pathogenic?

CHIA p.Val440Met (c.1318G>A) is classified Uncertain significance in CHIA (ClinVar, Single submitter, 1 submitter; last evaluated 2025-04-14). AlphaMissense: likely benign (0.1643); Ultra-rare (popmax 0.016%, afr).

How common is CHIA p.Val440Met (c.1318G>A) in the general population?

CHIA p.Val440Met (c.1318G>A) is ultra-rare (popmax 0.016%, afr) (gnomAD).

What do computational predictors say about CHIA p.Val440Met (c.1318G>A)?

AlphaMissense predicts likely benign (score 0.1643) — an in-silico prediction, not a clinical call.

CHIA p.Val440Met

c.1318G>A · VCV4002358

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.1643 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.016%, afr)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Computational evidence

Protein change
AlphaMissense	0.1643	likely benign
REVEL	0.036	moderately benign-leaning
SaProt	LLR -9.26	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 1	GERP -0.082, phastCons 0.001
Regional constraint	o/e 1.10	unconstrained · MANE · 9,995 bp · p 0.014 · regional, not allelic
Overall
CADD	10.24	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 0.016% African / African-American · 12/74,946 alleles

Filtering AF 0.00921% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00721%

Overall 0.00167% 27/1,614,118 alleles · ultra-rare

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.016%	6,246
South Asian	0.00988%	10,121
Remaining individualsnot grpmax-eligible	0.0016%	62,488
European (non-Finnish)	0.000424%	236,010

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: CHIA
Protein: p.Val440Met
Coding: c.1318G>A
MANE Select: NM_201653
Type: single nucleotide variant
Location: chr1:111320353 (GRCh38)
Gene constraint: LOEUF 1.063 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 92.65 · 8 PDB
Residue 440: the chitin-binding type-2 domain

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

Similar variants

CHIA p.Ala295Thr Benign/Likely benign ★★ same type
CHIA p.Ala57Thr Likely benign ★★ ⚠ same type
CHIA p.Arg35Trp Benign ★★ ⚠ same type
CHIA p.Gly317Glu Benign ★★ same type
CHIA p.Gly356= Benign ★★ same type
CHIA p.Ile272= Benign ★★ same type
CHIA p.Lys251= Benign ★★ same type
CHIA p.Ala182Thr Uncertain significance ★ ⚠ same type

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/chia-p-val440met (accessed [today's date]).

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