Is AMT p.Arg73His (c.218G>A) pathogenic?

AMT p.Arg73His (c.218G>A) is classified Uncertain significance in AMT (ClinVar, Multiple submitters, 3 submitters; last evaluated 2024-07-18). AlphaMissense: likely pathogenic (0.7494); Very rare (popmax 0.00223%, eas); Associated with glycine encephalopathy.

What condition is associated with AMT p.Arg73His (c.218G>A)?

AMT p.Arg73His (c.218G>A) is associated with glycine encephalopathy (ClinVar).

How common is AMT p.Arg73His (c.218G>A) in the general population?

AMT p.Arg73His (c.218G>A) is very rare (popmax 0.00223%, eas) (gnomAD).

How is Glycine encephalopathy inherited?

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

What do computational predictors say about AMT p.Arg73His (c.218G>A)?

AlphaMissense predicts likely pathogenic (score 0.7494) — an in-silico prediction, not a clinical call.

AMT p.Arg73His

c.218G>A · rs928833763 · VCV1465602

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

AlphaMissense

likely pathogenic

0.7494 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00223%, eas)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

glycine encephalopathy

Computational evidence

Protein change
AlphaMissense	0.7494	likely pathogenic
REVEL	0.836	moderately pathogenic-leaning
SaProt	LLR -14.03	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 2.1, phastCons 1
Regional constraint	o/e 0.93	unconstrained · MANE · 4,907 bp · p 0.12 · regional, not allelic
Overall
CADD	33.0	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean damaging — 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 0.00223% East Asian · 1/44,898 alleles

Filtering AF 0.000878% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000717%

Overall 0.0013% 21/1,613,716 alleles · very rare

Ancestry group	Frequency	1 in
East Asiangrpmax	0.00223%	44,898
Remaining individualsnot grpmax-eligible	0.0016%	62,482
European (non-Finnish)	0.00144%	69,414
African / African-American	0.00133%	74,936
South Asian	0.0011%	91,094

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: AMT
Protein: p.Arg73His
Coding: c.218G>A
MANE Select: NM_000481
dbSNP: rs928833763
Type: single nucleotide variant
Location: chr3:49422144 (GRCh38)
Gene constraint: LOEUF 0.805 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 93.66 · 2 PDB
Residue 73: an α-helix

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

Disease context

glycine encephalopathy — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Glycine encephalopathy (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy, Neonatal
Prevalence: 1-9 / 1 000 000 (Europe)

Similar variants

AMT p.Arg73Gly Likely pathogenic ★ same residue
AMT p.Arg73Cys Conflicting classifications of pathogenicity ★ ⚠ same residue
AMT p.Arg73fs Likely pathogenic ★ same residue
AMT p.Arg73Ser Uncertain significance ★ ⚠ same residue
AMT p.Arg73= Likely benign ★ same residue
AMT c.339+2T>C Likely pathogenic ★★ same condition
AMT c.471+2T>C Pathogenic ★★ same condition
AMT c.697-1G>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/amt-p-arg73his (accessed [today's date]).

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