Is FLNC p.Pro1221= (c.3663T>C) pathogenic?

FLNC p.Pro1221= (c.3663T>C) is classified Likely benign in FLNC (ClinVar, Single submitter, 1 submitter; last evaluated 2022-09-06). Absent from gnomAD v4.1; Associated with distal myopathy with posterior leg and anterior hand involvement.

What condition is associated with FLNC p.Pro1221= (c.3663T>C)?

FLNC p.Pro1221= (c.3663T>C) is associated with distal myopathy with posterior leg and anterior hand involvement, myofibrillar myopathy 5, hypertrophic cardiomyopathy 26 (ClinVar).

How common is FLNC p.Pro1221= (c.3663T>C) in the general population?

FLNC p.Pro1221= (c.3663T>C) is absent from gnomAD v4.1 (gnomAD).

FLNC p.Pro1221=

Q: How is FLNC-related handgrip and calf weakness-distal myopathy inherited?

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

c.3663T>C · rs369734958 · VCV1156682

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

distal myopathy with posterior leg and anterior hand involvement

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 -20
Overall
CADD	0.112	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: FLNC
Protein: p.Pro1221=
Coding: c.3663T>C
MANE Select: NM_001458
dbSNP: rs369734958
Type: single nucleotide variant
Location: chr7:128845128 (GRCh38)
Gene constraint: LOEUF 0.424 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)

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

Disease context

distal myopathy with posterior leg and anterior hand involvement — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: myofibrillar myopathy 5 hypertrophic cardiomyopathy 26

For FLNC-related handgrip and calf weakness-distal myopathy (Orphanet):

Inheritance: Autosomal dominant
Onset: Adolescent, Adult

Similar variants

FLNC p.Pro1221Leu Likely benign ★ same residue
FLNC c.1047+1G>T Likely pathogenic ★★ same condition
FLNC c.1048-1G>A Likely pathogenic ★★ same condition
FLNC c.1210+1G>A Likely pathogenic ★★ same condition
FLNC c.1549+2T>G Likely pathogenic ★★ same condition
FLNC c.2007+1G>A Likely pathogenic ★★ same condition
FLNC c.2550+1G>C Likely pathogenic ★★ same condition
FLNC c.2550+2T>C Pathogenic/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/flnc-p-pro1221 (accessed [today's date]).

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