Is AMN p.Arg299Trp (c.895C>T) pathogenic?

AMN p.Arg299Trp (c.895C>T) is classified Uncertain significance in AMN (ClinVar, Single submitter, 1 submitter; last evaluated 2024-05-30). AlphaMissense: likely benign (0.0855); Very rare (popmax 0.00571%, nfe); Associated with Imerslund-Grasbeck syndrome type 2.

What condition is associated with AMN p.Arg299Trp (c.895C>T)?

AMN p.Arg299Trp (c.895C>T) is associated with Imerslund-Grasbeck syndrome type 2 (ClinVar).

How common is AMN p.Arg299Trp (c.895C>T) in the general population?

AMN p.Arg299Trp (c.895C>T) is very rare (popmax 0.00571%, nfe) (gnomAD).

How is Imerslund-Gräsbeck syndrome inherited?

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

What do computational predictors say about AMN p.Arg299Trp (c.895C>T)?

AlphaMissense predicts likely benign (score 0.0855) — an in-silico prediction, not a clinical call.

AMN p.Arg299Trp

c.895C>T · VCV3576402

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0855 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00571%, nfe)

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL no call

Conditions

Imerslund-Grasbeck syndrome type 2

Computational evidence

Protein change
AlphaMissense	0.0855	likely benign
REVEL	0.309	indeterminate
SaProt	LLR -8.38	tolerated
⇒ AlphaMissense and SaProt both call this tolerated; REVEL makes no call.
Splicing
SpliceAI	<0.2	all four deltas below 0.2 · C>A here scores Δ0.24 · evaluated, not missing
Constraint at this position
Conservation	phyloP -1.5	GERP -1.4
Regional constraint	o/e 1.06	unconstrained · MANE · 7,988 bp · p 0.14 · regional, not allelic
Overall
CADD	18.11	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 0.00571% European (non-Finnish) · 66/1,155,762 alleles

Filtering AF 0.0046% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0042%

Overall 0.00454% 71/1,564,742 alleles · very rare

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.00571%	17,512
African / African-American	0.00544%	18,395
Remaining individualsnot grpmax-eligible	0.00165%	60,600

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: AMN
Protein: p.Arg299Trp
Coding: c.895C>T
MANE Select: NM_030943
Type: single nucleotide variant
Location: chr14:102929975 (GRCh38)
Gene constraint: LOEUF 1.446 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 80.78 · 1 PDB

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

Disease context

Imerslund-Grasbeck syndrome type 2 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Imerslund-Gräsbeck syndrome (Orphanet):

Inheritance: Autosomal recessive
Onset: Childhood
Prevalence: 1-9 / 1 000 000 (Finland)

Similar variants

AMN c.208-1G>C Pathogenic/Likely pathogenic ★★ same condition
AMN c.296-1G>A Likely pathogenic ★★ same condition
AMN c.44-1G>A Likely pathogenic ★★ same condition
AMN c.760+1G>A Likely pathogenic ★★ same condition
AMN c.844-1G>C Likely pathogenic ★★ same condition
AMN p.Thr41Ile Likely pathogenic ★★ ⚠ same condition
AMN c.296-3C>T Uncertain significance ★★ same condition
AMN c.651+3G>T 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/amn-p-arg299trp (accessed [today's date]).

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