A 17-Year-Old With Becker Muscular Dystrophy and Unusual Polysomnography Findings

A 17-year-old male patient who was diagnosed with Becker muscular dystrophy (nonsense mutation [c.3822C>A] within exon 28 of the DMD gene) at 6 years of age was evaluated in the multidisciplinary neuromuscular clinic for loss of ambulation for 1 year. From a pulmonary perspective, there were no acute or chronic respiratory symptoms, and no history of pneumonia or aspiration. Clinical examination revealed a nonambulant teenager, with normal oxygen saturation and end-tidal CO₂ when awake, no respiratory distress, and symmetrically diminished aeration due to obesity (BMI 40 kg/m²). Results of pulmonary function testing revealed FVC of 83% predicted with actual volume of 3.5 L and peak cough flow of 445 L/min (all within normal limits).