Is AGRN p.Ile656= (c.1968C>A) pathogenic?

AGRN p.Ile656= (c.1968C>A) is classified Likely benign in AGRN (ClinVar, Single submitter, 1 submitter; last evaluated 2026-01-23). Absent from gnomAD v4.1; Associated with congenital myasthenic syndrome 8.

What condition is associated with AGRN p.Ile656= (c.1968C>A)?

AGRN p.Ile656= (c.1968C>A) is associated with congenital myasthenic syndrome 8 (ClinVar).

How common is AGRN p.Ile656= (c.1968C>A) in the general population?

AGRN p.Ile656= (c.1968C>A) is absent from gnomAD v4.1 (gnomAD).

AGRN p.Ile656=

c.1968C>A · rs770946661 · VCV1137845

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

congenital myasthenic syndrome 8

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -6.6	GERP -2
Overall
CADD	1.435	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: AGRN
Protein: p.Ile656=
Coding: c.1968C>A
MANE Select: NM_198576
dbSNP: rs770946661
Type: single nucleotide variant
Location: chr1:1043992 (GRCh38)
Gene constraint: LOEUF 0.73 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 69.79 · 1 PDB
Residue 656: the kazal-like 7 domain

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

Disease context

congenital myasthenic syndrome 8 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

AGRN c.3632-1G>C Likely pathogenic ★★ same condition
AGRN p.Arg1671Ter Pathogenic/Likely pathogenic ★★ same condition
AGRN p.Arg834Ter Pathogenic/Likely pathogenic ★★ same condition
AGRN p.Gly1582Arg Pathogenic ★★ same condition
AGRN p.Gly1675Ser Pathogenic/Likely pathogenic ★★ same condition
AGRN c.1177+4A>G Uncertain significance ★★ same condition
AGRN c.1384+6C>T Uncertain significance ★★ same condition
AGRN c.4879+4G>A 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/agrn-p-ile656 (accessed [today's date]).

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