D-Cycloserine for Serine Palmitoyltransferase Inhibition

Inclusion Criteria: * • Informed consent provided by the participant's parents. * Ability to travel to the study and assessment sites (Massachusetts General Hospital Main Campus, 55 Fruit St, Boston, MA 02114 and MGH IHP Impact Practice Center, 2 Constitution Wharf, Charlestown, MA 02129) and adhere to study-related follow-up examinations and/or procedures and provide access to participant's medical records. * Clinical phenotype, neuroimaging, genetic testing and biochemical results consistent with a diagnosis of SPTSSA-related Complex Hereditary Spastic Paraplegia Exclusion Criteria: * • Participant has any known contraindication to or unwillingness to undergo procedures listed in the protocol * Use of investigational medication within 5 half-lives of the drug at enrollment * Participant has any condition that, in the opinion of the Site Investigator, would ultimately prevent the completion of study procedures.