Is AMN p.Thr41= (c.123C>G) pathogenic?

AMN p.Thr41= (c.123C>G) is classified Likely benign in AMN (ClinVar, Single submitter, 1 submitter; last evaluated 2025-08-26). Ultra-rare (popmax 0.0167%, amr); Associated with Imerslund-Grasbeck syndrome.

What condition is associated with AMN p.Thr41= (c.123C>G)?

AMN p.Thr41= (c.123C>G) is associated with Imerslund-Grasbeck syndrome (ClinVar).

How common is AMN p.Thr41= (c.123C>G) in the general population?

AMN p.Thr41= (c.123C>G) is ultra-rare (popmax 0.0167%, amr) (gnomAD).

How is Imerslund-Gräsbeck syndrome inherited?

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

AMN p.Thr41=

c.123C>G · rs758005290 · VCV727345

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.0167%, amr)

Conditions

Imerslund-Grasbeck syndrome

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	<0.2	no splice effect predicted · four deltas, not one · how we know
Constraint at this position
Conservation	phyloP -3	GERP -2.6
Overall
CADD	5.738	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0167% Admixed American · 10/60,006 alleles

Filtering AF 0.009% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00681%

Overall 0.00136% 22/1,612,662 alleles · ultra-rare exomes 17/1,460,394 · genomes 5/152,268 · joint denominator

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.0167%	6,001
Remaining individualsnot grpmax-eligible	0.0112%	8,923
African / African-American	0.00133%	74,948
European (non-Finnish)	0.000339%	294,968

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.Thr41=
Coding: c.123C>G
MANE Select: NM_030943
dbSNP: rs758005290
Type: single nucleotide variant
Location: chr14:102923790 (GRCh38)
Gene constraint: LOEUF 1.446 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 80.78 · 1 PDB
Residue 41: a UniProt-annotated variant site (in igs2; reduced presence at the cell membrane; loss of interaction with cubn; reduced cubn expression at the cell surface); an α-helix

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

Disease context

Imerslund-Grasbeck syndrome — 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 p.Thr41Ile Likely pathogenic ★★ ⚠ same residue
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.Trp391Ter Pathogenic/Likely pathogenic ★★ same condition
AMN c.296-3C>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-thr41 (accessed [today's date]).

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