Is AMPD1 p.Tyr606Ter (c.1818C>G) pathogenic?

AMPD1 p.Tyr606Ter (c.1818C>G) is classified Likely pathogenic in AMPD1 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-07-29). Very rare (popmax 0.00134%, afr); Associated with myopathy due to myoadenylate deaminase deficiency.

What condition is associated with AMPD1 p.Tyr606Ter (c.1818C>G)?

AMPD1 p.Tyr606Ter (c.1818C>G) is associated with myopathy due to myoadenylate deaminase deficiency (ClinVar).

How common is AMPD1 p.Tyr606Ter (c.1818C>G) in the general population?

AMPD1 p.Tyr606Ter (c.1818C>G) is very rare (popmax 0.00134%, afr) (gnomAD).

AMPD1 p.Tyr606Ter

c.1818C>G · VCV4850643

Likely pathogenic Single submitter

Classification

Likely pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

nonsense (stop-gain)

predicted LoF

gnomAD v4.1

Rare

very rare (popmax 0.00134%, afr)

Conditions

myopathy due to myoadenylate deaminase deficiency

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	nonsense (stop-gain)	predicted loss-of-function
NMD	predicted	premature termination codon in exon 14 of 16
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 0.69	GERP -3.7, phastCons 0.44
Overall
CADD	37.0	PHRED · no single calibrated threshold — expert panels disagree

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00134% African / African-American · 1/74,894 alleles

Overall 0.000658% 1/152,078 alleles · very rare

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: AMPD1
Protein: p.Tyr606Ter
Coding: c.1818C>G
MANE Select: NM_000036
Type: single nucleotide variant
Location: chr1:114674065 (GRCh38)
Gene constraint: LOEUF 1.036 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 86.84

Full AMPD1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

myopathy due to myoadenylate deaminase deficiency — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

AMPD1 p.Gln653Ter Pathogenic/Likely pathogenic ★★ same condition
AMPD1 c.1388+5G>A Uncertain significance ★★ same condition
AMPD1 c.1974+1G>A Uncertain significance ★★ same condition
AMPD1 c.-42C>T Uncertain significance ★★ ⚠ same condition
AMPD1 p.Ala308Thr Uncertain significance ★★ ⚠ same condition
AMPD1 p.Ala489Thr Uncertain significance ★★ ⚠ same condition
AMPD1 p.Ala578Thr Uncertain significance ★★ ⚠ same condition
AMPD1 p.Ala616Thr 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/ampd1-p-tyr606ter (accessed [today's date]).

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