Patient with spinal muscular atrophy with respiratory distress type 1 presenting initially with hypertonia

Area of Science:

• Genetics
• Neuromuscular Disorders
• Rare Diseases

Background:

• Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is an autosomal recessive neuromuscular disorder.
• Caused by IGHMBP2 gene mutations, it typically presents with severe respiratory distress in infants.
• Characterized by diaphragmatic paralysis, leading to life-threatening respiratory compromise.

Observation:

• A two-month-old boy presented with initial hypertonia, progressing to hypotonia.
• Unique symptoms included bone tissue compromise, deviating from typical SMARD1 presentations.
• Muscle biopsy revealed mild myogenic changes.

Findings:

• The patient was misdiagnosed initially, underscoring diagnostic challenges.
• Genetic screening confirmed the diagnosis of SMARD1.
• This case demonstrates significant clinical heterogeneity within SMARD1.

Implications:

• This case expands the known phenotypic spectrum of SMARD1.
• Highlights the importance of genetic testing for accurate diagnosis.
• Contributes to a broader understanding of IGHMBP2-related disorders.