Spinal muscular atrophy (SMA) is the most common cause of neurogenic hypotony in early infancy. The disease consists of four forms: type 0, type 1, type 2, and type 3, according to the age of onset, clinic severity and prognosis. SMA type 0 is the rarest and the most fatal type of the disease. SMA causes profound hypotony, severe weakness and often fatal restrictive pulmonary disease. The most common selective features of SMA type 0 are reduced fetal movements, severe weakness including of respiratory muscles and hypotony at birth, and fatal prognosis. To emphasize the importance of the distinctive diagnosis of the hypotonic newborn with respiratory distress, we present a rare SMA type 0 case with fetal hypokinesia, severe weakness including respiratory muscles requiring ventilator support at birth, arthrogryposis multiplex congenita (AMC), and deletions on exons 7 and 8 on Survival of Motor Neuron gene (SMN1). Anahtar Kelimeler : spinal müsküler atrofi, artrogriposis multipleks konjenita.