The aim of this study is to determine the clinical spectrum and natural progression of Hereditary Spastic Paraplegias (HSP) and related disorders in a prospective multicenter natural history study, identify digital, imaging and molecular biomarkers that can assist in diagnosis and therapy development and study the genetic etiology and molecular mechanisms of these diseases.

The investigators will perform a registry-based standardized prospective Natural History Study (NHS) in HSPs and related disorders. Participants will be seen annually. At study visits a standardized clinical examination will be performed including application of clinical rating scales (selection of rating scales may vary depending on the individual phenotype and specific genotype); data will be entered into a clinical database (HSP Registry; https://www.hsp-registry.net). At all study visits, patients will be asked to donate biosamples; biomaterial collection is optional and participants can elect to participate in sampling of blood, urine, CSF, and/or a skin biopsy.

Optionally, additional examinations may be performed including imaging, quantitative movement analysis, neuropsychological examinations, analysis of patient or observer reported outcomes and OMICS analysis to characterize molecular biomarkers.

In participants without a genetic diagnosis, next generation sequencing may be performed.

Inclusion criteria:

• One of the following:

  1. Primary participant: Clinical or genetic diagnosis of HSP or a related disorder

  2. Secondary participant: Unaffected family member (1st or 2nd degree relative) of primary participant (with the above-mentioned restrictions for special populations) able to give informed consent

  3. Unrelated healthy control able to give informed consent

     AND

• Written informed consent

AND

- Participants are willing and able to comply with study procedures

Exclusion criteria:

• Missing informed consent of primary or secondary participant/ healthy control/ legal representatives
• For controls: evidence of a neurodegenerative disease or movement disorders; inability to give informed consent

Probands with a clinical or genetic diagnosis of an HSP and related disorders including pre-manifest individuals will be primarily enrolled in this study (primary participants).

Additionally, unaffected family members of primary participants will be enrolled if they are of legal age (>= 18 years) and able to give informed consent (secondary participants).

Unaffected minors will only be enrolled under special circumstances as detailed in paragraph 5.1 (Special Populations - Unaffected minors).

Lastly, healthy unrelated controls will be enrolled; these are necessary to contrast unspecific, gender- or age-related findings to disease specific findings.