Infantile spinal muscular atrophy (morbus Werdnig-Hoffmann) causing neonatal asphyxia

Area of Science:

• Neurology
• Pediatrics
• Genetics

Background:

• Infantile spinal muscular atrophy (SMA), also known as Werdnig-Hoffmann disease, is a severe genetic neuromuscular disorder.
• It is characterized by progressive muscle weakness and atrophy due to the degeneration of motor neurons in the spinal cord.
• While typically presenting with hypotonia and motor deficits, severe neonatal onset with respiratory compromise is less common.

Observation:

• A neonate presented with complete proximal paresis, extreme floppiness, and reduced fetal movements from the 32nd week of gestation.
• Clinical signs included limited spontaneous movements (hands, feet, face), tongue fibrillations, diaphragmatic hemiparesis, and dysphagia.
• The infant experienced neonatal asphyxia, indicating severe respiratory muscle involvement.

Findings:

• The infant's condition was incompatible with unassisted ventilation, leading to death during the neonatal period.
• Muscle biopsy and autopsy confirmed the diagnosis of infantile spinal muscular atrophy.
• This presentation highlights a rare and severe form of SMA leading to fatal neonatal asphyxia.

Implications:

• This case underscores the importance of considering neuromuscular disorders, such as spinal muscular atrophy, in neonates with unexplained hypotonia and respiratory distress.
• Early recognition of potential neuromuscular causes for neonatal asphyxia is critical for appropriate management and genetic counseling.
• The unusual severity and presentation emphasize the spectrum of infantile spinal muscular atrophy and its potential impact on neonatal survival.