The Werdnig-Hoffmann disease, also known as spinal muscular atrophy, is a hereditary and familial syndrome which affects children. It begins with atrophy of the pelvitrochanteric muscles (of the pelvis and hip joints); as a result, the patient is unable to sit or stand up. Reflexes are abolished, but there is no alteration of sensitivity. Over time, the atrophy extends to the upper limbs and thorax. The Werdnig-Hoffmann disease progresses slowly, eventually leading to death after six or seven years of its onset, due to paralysis of thoracic respiratory muscles. This muscular atrophy, or paralysis, is the result of death and degeneration of motor neurons in the spinal cord anterior horns and in the brainstem.