Andermann syndrome is an inherited disorder that leads to progressive nervous system damage.
Andermann syndrome presents early in life with symptoms like intellectual and developmental disabilities, delayed motor skills, muscle weakness, spinal curvature, and nerve dysfunction in the hands and feet resulting in numbness, pain, and weakness. These symptoms worsen over time, affecting both motor and sensory skills, and are accompanied by specific physical features such as a small head size, long asymmetric face, small upper jaw, large ears, and widely spaced eyes. Two-thirds of affected individuals lack a fully formed corpus callosum in the brain, impacting brain communication, and experience delayed walking, seizures, and eventual loss of mobility in their early teens. As the disease progresses, individuals may also develop hallucinations and psychosis in their twenties, and unfortunately, Andermann syndrome is typically fatal before the age of 40.
Andermann syndrome is caused by pathogenic (disease-causing) variants in the SLC12A6 gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Ashkenazi Jewish descent have a 1 in 1641 chance to be a carrier.
Other names for this condition are agenesis of corpus callosum with neuropathy, agenesis of corpus callosum with peripheral neuropathy, agenesis of corpus callosum with polyneuropathy, Charlevoix disease, and hereditary motor and sensory neuropathy with agenesis of the corpus callosum.