Ultrasound evaluation of diaphragm motion in BAG-3 myofibrillar myopathy: A case report

Medicine (Baltimore). 2022 Jan 7;101(1):e28484. doi: 10.1097/MD.0000000000028484.

Abstract

Rationale: Mutations in Bcl-2-associated athanogene-3 (BAG-3) can cause a rare subtype of myofibrillar myopathies (MFMs), characterized by progressive muscle weakness, cardiomyopathy, and severe respiratory insufficiency in childhood. Little is known about diaphragmatic function in BAG-3 MFM. To our knowledge, this is the first case report of detailed evaluation of diaphragmatic function with ultrasound in BAG-3 MFM.

Patient concern: We describe the case of a 15-year-old girl who complained of fever and shortness of breath. Diaphragmatic sonography revealed bilateral diaphragmatic paralysis. Shortness of breath progressed to respiratory failure approximately 3 months later.

Diagnosis: A neurologist was consulted and genetic sequencing identified a p.Pro209Leu mutation in BAG-3, yielding diagnosis of BAG-3 MFM leading to bilateral diaphragmatic paralysis.

Interventions: Respiratory muscle training and long-term mechanical ventilation.

Outcomes: It is quite unfortunate for this patient to have a poor prognosis due to the lack of effective treatment for this genetic disorder.

Lessons: This case provides more clinical information for this rare disease which may cause severe diaphragm pathological damage leading to respiratory failure in BAG3 MFM and a future study with a systematic evaluation of a greater number of patients will be necessary to characterize this population.

Publication types

  • Case Reports

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adolescent
  • Apoptosis Regulatory Proteins / genetics
  • Diaphragm / diagnostic imaging*
  • Dyspnea
  • Female
  • Humans
  • Muscle Weakness
  • Myopathies, Structural, Congenital / genetics*
  • Respiratory Paralysis*
  • Transcription Factors

Substances

  • Adaptor Proteins, Signal Transducing
  • Apoptosis Regulatory Proteins
  • BAG3 protein, human
  • Transcription Factors

Supplementary concepts

  • Myofibrillar Myopathy