The Registry and Natural History Study for Early Onset Hereditary Spastic Paraplegia (HSP) is focused on gathering longitudinal clinical data as well as biological samples (skin and/or blood and/or saliva) from male and female patients, under the age of 30, who exhibited early onset symptoms of HSP with (1) a clinical diagnosis of hereditary spastic paraplegia and (2) the presence of variants in HSP related genes and/or be a relative of a person with such a diagnosis. Currently, the treatment for this disorder is generally symptomatic and available therapies improve quality of life, but are grossly inefficient in slowing the disease progression. Access to the registry information will be limited to the study staff who are responsible for recruitment and maintenance of the registry. We hope that recruitment into the registry for studies will advance knowledge of the causes, clinical course, diagnosis, and treatment of these conditions.

The hereditary spastic paraplegias (HSP) are a group of more than 80 neurodegenerative diseases that lead to progressive neurological decline. Collectively, the HSPs present the most common cause of inherited spasticity and associated disability.

We aim to delineate the core clinical, imaging, and molecular features of pediatric onset hereditary spastic paraplegia. This registry and natural history study will facilitate an early diagnosis, enables counseling and anticipatory guidance of affected families and will help define clinically meaningful endpoints for future interventional trials. Samples will be collected for the purpose of molecular and cellular investigation that will help identify biomarkers and novel targets for therapy. The samples and clinical information will be housed in the Translational Neuroscience Center and a secure REDcap database, respectively; both located in Boston Children's Hospital (BCH), but will be available to investigators around the world after approval.

The objectives of this protocol are to (1) To systematically document the clinical presentation and natural history of early-onset forms of HSP and (2) To facilitate an early diagnosis, enable counseling and anticipatory guidance of affected families and help define clinically meaningful endpoints for future interventional traits.

Specifically, the aims are to:

1. Establish the disease spectrum through a cross-sectional analysis of clinical, imaging and molecular data
2. Establish the natural history of early-onset HSP through longitudinal clinician- and patient-reported outcome measures
3. Create a biorepository (blood samples, fibroblasts, induced pluripotent stem cells)
4. Create a registry that allows for re-identification and re-contact of participants by appropriate investigators

Inclusion Criteria:

• Onset of hereditary spastic paraplegia symptoms before the age of 18 years
• Under the age of 30 years old
• Must have a genetically confirmed variant in HSP-related genes and a relative of an individual with a confirmed diagnosis (if applicable).

Exclusion Criteria:

• Not having such a diagnosis and/or not being related to such individual

The study population consists of male and female patients up to the age of 30 years old with a clinical and molecular diagnosis of hereditary spastic paraplegia and/or their family members of interest (if applicable).