Inheritance from both parents will result in the disease
Age range at onset:
Below age 7
Specialists you may see:
Delayed development followed by clumsiness and unsteady walking are usually the first symptoms of GAN which presents usually before the age of 7 years.
Walking will become increasingly difficult, followed by numbness in the arms and legs and sometimes seizures. Speech problems, swallowing difficulties, hearing problems, abnormal vision and eye movements and cognitive difficulties often develop. Characteristically, those with GAN have dull, tightly curled hair of a different colour and texture to that of their parents.
Loss of ability to sweat, constipation and bladder problems as well as intolerance to heat are common.
Those with GAN experience worsening seizures, as well as symptoms such as paralysis and dementia. Most do not live past their 20s.
Mutations of the GAN1 gene, which creates a protein called gigaxonin, are responsible for Giant Axonal Neuropathy. Gigaxonin breaks down neurofilaments which regulate the size of axons (Axons allow neurons to communicate with other cells). When production of gigaxonin is disrupted, these neurofilaments are not broken down and become densely packed, causing axons to swell. These axons are then unable to transmit signals properly, causing the symptoms described.