Noisy breathing and hemidiaphragm paralysis progressing to respiratory failure in an infant.

Spinal muscular atrophy with respiratory distress (SMARD1) is a rare autosomal recessive disease that is caused by mutations in the gene encoding for immunoglobulin µ-binding protein 2. Unlike the relatively more common spinal muscular atrophy, patients with SMARD1 have respiratory distress prior to manifestation of distal muscle weakness making the diagnosis a challenge. Because respiratory distress is a hallmark feature of this disease, pediatric pulmonologists should recognize its features, and consider it as a diagnostic entity.