Infantile Hypotonia: A Case of Spinal Muscular Atrophy With Respiratory Distress Type 1 Presenting As Infant Botulism

Area of Science:

• Neurology
• Genetics
• Pediatrics

Background:

• Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a rare, severe autosomal recessive neuromuscular disorder.
• SMARD1 presents in early infancy (6 weeks to 6 months) with progressive distal muscle atrophy and significant respiratory distress, often requiring ventilatory support.
• Currently, no curative treatments exist for SMARD1; management focuses on supportive care to mitigate clinical decline.

Observation:

• A 12-week-old infant presented with symptoms mimicking infant botulism, including respiratory distress and hypotonia, following honey exposure.
• Infant botulism and SMARD1 share overlapping clinical features, such as respiratory compromise, decreased muscle tone, and autonomic dysfunction, typically appearing before one year of age.
• The infant's initial diagnosis of infant botulism was reconsidered due to a lack of response to standard treatments.

Findings:

• This case highlights the diagnostic challenge posed by the clinical similarities between SMARD1, SMA Type 1, and infant botulism.
• The overlapping symptomatology underscores the importance of considering rare genetic disorders in the differential diagnosis of infantile hypotonia and respiratory failure.
• Failure to respond to treatments for presumed infant botulism should prompt re-evaluation for alternative diagnoses like SMARD1.

Implications:

• Broadening the differential diagnosis for infantile hypotonia and respiratory distress is critical for timely and accurate diagnosis.
• Recognizing the shared clinical features between SMARD1 and infant botulism can prevent diagnostic delays and ensure appropriate management strategies are initiated.
• This case emphasizes the need for vigilant clinical assessment and consideration of less common conditions, particularly when infants do not improve with initial interventions.