Seventeen children with Behr syndrome were investigated, focusing on the musculoskeletal deformities and long-term outcome. Behr syndrome is characterized by optic atrophy beginning in early childhood associated with ataxia, spasticity, mental retardation, and posterior column sensory loss. The ataxia, spasticity, and muscle contractures, mainly of the hip adductors, hamstrings, and soleus, are progressive and become more prominent in the second decade. In 70% of the patients, contractures developed in the lower limbs, requiring surgery mainly for the Achilles tendon, hamstrings, and adductor longus. At last follow-up at an average age of 21.7 years (range, 8-31 years), 13 of the patients are housebound walkers, 2 are nonfunctional walkers, and 2 are nonwalkers.