Study Identifies PTCD1 Gene Variants Causing Mitochondrial Protein Aggregation and Cardiomyopathy
Researchers identified three pathogenic variants in the PTCD1 gene that cause infantile cardiomyopathy through impaired mitochondrial protein processing and aggregation. The study demonstrates that disrupted mitoribosome biogenesis—not just energy metabolism defects—contributes to tissue damage in PTCD1 deficiency. This finding expands understanding of mitochondrial disease mechanisms and may inform future therapeutic approaches targeting proteotoxic stress.
A bioRxiv preprint describes the characterization of three PTCD1 variants (p.Arg113Trp, p.Gly184Arg, and p.Arg130*) identified in a child with infantile cardiomyopathy and combined respiratory chain deficiency. Using patient cardiac tissue analysis and cell models, researchers found that these variants impair mitoribosome biogenesis and trigger selective aggregation of mitochondrial matrix proteins, accompanied by altered OPA1 processing and mitochondrial network remodeling. The cis combination of p.Arg113Trp and p.Gly184Arg produced the most severe protein aggregation phenotype. The work establishes that proteotoxic stress from impaired mitoribosome assembly—beyond simple energy metabolism dysfunction—drives pathology in post-mitotic tissues like the heart, providing mechanistic insight into PTCD1-related cardiomyopathy.
Limitations & open questions
The preprint does not specify whether these findings have been validated in independent patient cohorts or whether functional rescue experiments (e.g., therapeutic interventions targeting proteostasis) were attempted. The study's own limitations regarding generalizability to other PTCD1 variants and tissues are not explicitly discussed in the provided abstract.
What different sources said
- bioRxivCenter
Pathogenic PTCD1 variants cause mitochondrial protein aggregation and cardiomyopathy
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