Is TTN p.Arg26331= (c.78993A>G) pathogenic?

TTN p.Arg26331= (c.78993A>G) is classified Conflicting classifications of pathogenicity in TTN (ClinVar, Conflicting submitters, 4 submitters; last evaluated 2026-01-26). Very rare (popmax 0.0039%, nfe); Associated with Cardiovascular phenotype.

What condition is associated with TTN p.Arg26331= (c.78993A>G)?

TTN p.Arg26331= (c.78993A>G) is associated with Cardiovascular phenotype, dilated cardiomyopathy 1G, autosomal recessive limb-girdle muscular dystrophy type 2J (ClinVar).

How common is TTN p.Arg26331= (c.78993A>G) in the general population?

TTN p.Arg26331= (c.78993A>G) is very rare (popmax 0.0039%, nfe) (gnomAD).

TTN p.Arg26331=

c.78993A>G · rs745659756 · VCV467518

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 4 submitters

gnomAD v4.1

Rare

very rare (popmax 0.0039%, nfe)

Conditions

Cardiovascular phenotype

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 -0.14	GERP -5.9, phastCons 0.72
Overall
CADD	0.191	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0039% European (non-Finnish) · 46/1,179,618 alleles

Filtering AF 0.00299% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00267%

Overall 0.00298% 48/1,613,420 alleles · very rare

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.0039%	25,644
Remaining individualsnot grpmax-eligible	0.0016%	62,446
African / African-American	0.00134%	74,894

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.Arg26331=
Coding: c.78993A>G
MANE Select: NM_001267550
dbSNP: rs745659756
Type: single nucleotide variant
Location: chr2:178567139 (GRCh38)
Gene constraint: LOEUF 0.479 · pLI <0.01 · ClinGen HI 2/3 (gnomAD)
Residue 26331: the ig-like 127 domain

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

Disease context

Cardiovascular phenotype — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: dilated cardiomyopathy 1G autosomal recessive limb-girdle muscular dystrophy type 2J

Similar variants

TTN p.Arg26331Ter Pathogenic/Likely pathogenic ★★ same residue
TTN p.Arg26331Gln Likely benign ★★ same residue
TTN c.100171+1G>A Likely pathogenic ★★ same condition
TTN c.100766-1G>T Likely pathogenic ★★ same condition
TTN c.100766-2A>T Likely pathogenic ★★ same condition
TTN c.106375-2A>G Pathogenic/Likely pathogenic ★★ same condition
TTN c.106531+1G>A Pathogenic/Likely pathogenic ★★ same condition
TTN c.107224-1G>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/ttn-p-arg26331 (accessed [today's date]).

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