Is TTN p.Pro22055= (c.66165A>C) pathogenic?

TTN p.Pro22055= (c.66165A>C) is classified Likely benign in TTN (ClinVar, Single submitter, 1 submitter; last evaluated 2025-10-13). Very rare (popmax 0.000255%, nfe); Associated with dilated cardiomyopathy 1G.

What condition is associated with TTN p.Pro22055= (c.66165A>C)?

TTN p.Pro22055= (c.66165A>C) is associated with dilated cardiomyopathy 1G, autosomal recessive limb-girdle muscular dystrophy type 2J (ClinVar).

How common is TTN p.Pro22055= (c.66165A>C) in the general population?

TTN p.Pro22055= (c.66165A>C) is very rare (popmax 0.000255%, nfe) (gnomAD).

How is Familial isolated dilated cardiomyopathy inherited?

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

TTN p.Pro22055=

c.66165A>C · VCV4784593

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.000255%, nfe)

Conditions

dilated cardiomyopathy 1G

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not looked up on this page · why
Constraint at this position
Conservation	phyloP -0.24	GERP -4.8, phastCons 0.43
Overall
CADD	0.383	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000255% European (non-Finnish) · 3/1,177,266 alleles

Filtering AF 6.8e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 1.9e-05%

Overall 0.000207% 3/1,451,454 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: TTN
Protein: p.Pro22055=
Coding: c.66165A>C
Type: single nucleotide variant
Location: chr2:178582204 (GRCh38)

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

Disease context

dilated cardiomyopathy 1G — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: autosomal recessive limb-girdle muscular dystrophy type 2J

For Familial isolated dilated cardiomyopathy (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive, Mitochondrial inheritance
Onset: All ages
Prevalence: 1-9 / 100 000 (Europe)

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/ttn-p-pro22055 (accessed [today's date]).

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