Related Experiment Videos
Infantile intranuclear rod myopathy
H H Goebel1, A Piirsoo, I Warlo
1Department of Neuropathology, Mainz University Medical Center, Germany.
Insights
This study details three infants with severe nemaline myopathy, characterized by intranuclear rods. The presence of these rods, particularly in infants, indicates a poor prognosis for rod myopathy.
Area of Science:
- Neurology
- Pediatrics
- Muscle Biology
Background:
- This study investigates three unrelated infants diagnosed with severe hypotonia and respiratory failure at one month of age.
- All infants required mechanical ventilation from birth, highlighting the critical nature of their condition.
Observation:
- Muscle biopsies revealed abundant intranuclear rods in all three infants.
- Sarcoplasmic rods were present in two infants, but absent in one girl, even upon autopsy.
Findings:
- Immunoelectron microscopy using an anti-alpha-actinin antibody confirmed the Z-band origin of both sarcoplasmic and intranuclear rods.
- This is the first report of rod myopathy exclusively with intranuclear rods and the initial demonstration of alpha-actinin within these intranuclear structures.
Implications:
- The exclusive presence of intranuclear rods in infantile nemaline myopathy suggests a severe disease course.
- Intranuclear rods in infants with nemaline myopathy are associated with a grave prognosis, emphasizing the need for early diagnosis and management.
Abstract:
This report concerns three unrelated floppy infants, two girls and one boy, each biopsied at the age of 1 month. They were hypotonic since birth and required artificial ventilation. The two girls died at the ages of 4 and 3 1/2 months, respectively, the boy is still alive at the age of 2 years, but requires assisted ventilation. Each of the three infants showed, by muscle biopsy, abundant intranuclear rods, the boy and one girl also had sarcoplasmic rods, which were not present in the other girl's muscle. Absence of sarcoplasmic rods, but the presence of intranuclear rods could also be documented in her autopsied muscle. Using an antibody against alpha-actinin, immunoelectron microscopy showed reaction of the sarcoplasmic and intranuclear rods demonstrating their Z-band origin. To our knowledge, this is the first report on rod myopathy with intranuclear rods only and of an immunoelectron microscopic demonstration of alpha-actinin in intranuclear rods. The presence of intranuclear rods in infants with nemaline myopathy also appears to indicate a grave prognosis of their rod myopathy.