Primary mitochondrial disease as a rare cause of unclear breathlessness and distinctive performance degradation – a case report 2023 Ewert et al

Abstract

Background
Primary muscular disorders (metabolic myopathies, including mitochondrial disorders) are a rare cause of dyspnea. We report a case of dyspnea caused by a mitochondrial disorder with a pattern of clinical findings that can be classified in the known pathologies of mitochondrial deletion syndrome.

Case presentation
The patient presented to us at 29 years of age, having had tachycardia, dyspnea, and functional impairment since childhood. She had been diagnosed with bronchial asthma and mild left ventricular hypertrophy and treated accordingly, but her symptoms had worsened. After more than 20 years of progressive physical and social limitations was a mitochondrial disease suspected in the exercise testing. We performed cardiopulmonary exercise testing (CPET) with right heart catheterization showed typical signs of mitochondrial myopathy. Genetic testing confirmed the presence of a ~ 13 kb deletion in mitochondrial DNA from the muscle. The patient was treated with dietary supplements for 1 year. In the course of time, the patient gave birth to a healthy child, which is developing normally.

Conclusion
CPET and lung function data over 5 years demonstrated stable disease. We conclude that CPET and lung function analysis should be used consistently to evaluate the cause of dyspnea and for long-term observation.

Open access, https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-023-02391-x

 

Wow, she lost 13kb of her mtDNA; a healthy person has 16kb. I can't believe that's survivable. If before I saw this article, you asked me what would happen to someone who didn't inherit 80% of their mitochondrial DNA, I would have said they wouldn't even be born. How is this possible?

 

From Mitochondria and Diseases (ScienceDirect)

 

Oh, so this person had the deletion in only 36% of her cells?