Hereditary spastic paraplegias (HSPs) are a group of inherited disorders which affect the long motor fiber tracts in the spinal cord, causing stiffness and weakness especially in the muscles of the lower body as the key symptom. Gait difficulties gradually worsen over time and patients may eventually require a walking aid or a wheelchair. The disease cannot yet be cured, but there are some treatments available which help to relieve symptoms.
HSP can start at almost any age, but most commonly, symptoms begin in mid-adulthood.
In many cases, HSP is caused by one copy of a faulty gene inherited from a parent – this is known as an autosomal dominant pattern of inheritance. However, in other cases both parents are healthy and the disease follows a recessive trait. In autosomal recessive disease, parents do not develop HSP but they are ‘carriers’ of the mutation. Only if both, the paternal and the maternal, mutations are transmitted to a child this will develop HSP. The faulty gene involved varies depending on the type of HSP.