Hereditary spastic paraplegia is a general term for a group of rare inherited disorders that cause weakness and stiffness in the leg muscles. Symptoms gradually get worse over time.
It's also known as familial spastic paraparesis or Strümpell-Lorrain syndrome.
It's difficult to know exactly how many people have hereditary spastic paraplegia because it's often misdiagnosed. It's thought to affect about 3 in every 100,000 people.
The severity and progression of symptoms will vary from person to person.
About 90% of people with hereditary spastic paraplegia have a pure form. Their symptoms are mainly confined to lower limb weakness and involuntary spasms and muscle stiffness (spasticity).
The remaining 10% have a complicated or complex form of the condition. This means they have other symptoms in addition to the muscle weakness and spasticity. They may have a wide range of symptoms.
Children may develop leg stiffness and problems walking, such as stumbling and tripping, particularly on uneven ground. This is because it's difficult for them to bend their toes upwards as a result of having weak hip muscles.
Some people may eventually need to use a walking cane or a wheelchair to help them get around. Others may not need to use any type of mobility equipment.
What causes hereditary spastic paraplegia?
Most people with pure hereditary spastic paraplegia will have inherited a faulty gene from one of their parents.
People with the complicated form of the condition will have usually inherited a faulty gene from both parents.
The gene abnormality causes the long nerves in the spine to deteriorate. These nerves normally control muscle tone and movement in the lower body.
Hereditary spastic paraplegia is diagnosed following a thorough clinical examination and the identification of typical symptoms.
Other conditions that cause mobility problems and muscle stiffness and weakness, such as multiple sclerosis and cerebral palsy, need to be ruled out first.
A number of specialised tests may be used during diagnosis, including (MRI scans of the brain and spine, cerebrospinal fluid analysis, nerve conduction tests and an EMG.
In some cases, genetic testing may also be needed.
It isn't possible to prevent, slow or reverse hereditary spastic paraplegia, but some of the symptoms can be managed so that day-to-day activities become easier.
The outlook for people with hereditary spastic paraplegia varies. Some people are severely affected and need a wheelchair, while others have mild symptoms and don't need to use a mobility aid.
The condition doesn't usually affect life expectancy, and most people are able to lead relatively independent and active lives.
If you or your child has hereditary spastic paraplegia, your clinical team may pass information about you/your child on to the National Congenital Anomaly and Rare Diseases Registration Service (NCARDRS).
The NCARDRS helps scientists identify more effective ways of treating or preventing rare conditions. You can opt out of the register at any time.
Find out more about the NCARDRS register.