Andermann syndrome (AS) is a disorder that damages the nerves used for muscle movement and sensation (motor and sensory neuropathy). Agenesis or malformation of the corpus callosum also occurs in most people with this disorder. Signs and symptoms of the disorder include areflexia; hypotonia; amyotrophy; severe progressive weakness and loss of sensation in the limbs; and tremors. Other features may include intellectual disability, seizures, contractures, scoliosis, various psychiatric symptoms, various atypical physical features, and cranial nerve problems that cause facial muscle weakness, ptosis, and difficulty following movements with the eyes (gaze palsy). It is caused by genetic changes in the SLC12A6 gene and is inherited in an autosomal recessive manner.