Leigh Syndrome

The main goal of the project is provision of a global registry for mitochondrial disorders to harmonize previous national registries, enable world-wide participation and facilitate natural history studies, definition of outcome measures and conduction of clinical trials.

The goal of this clinical trial is to investigate oral TTI-0102 to evaluate its pharmacokinetics, safety, and preliminary efficacy in patients with Leigh syndrome spectrum, in three sequences. First sequence will be placebo-controlled and include 12 adolescents and adults weighing more than 40 kg. Second sequence will be open-label and include 3 adults and 3 children weighing 25-40 kg. Third sequence will also be open-label and will include 3 children weighing 20-25 kg. The main questions clinical trial aims to answer are: * Characterize the relationship between TTI-0102 drug levels by measuring 1. cysteamine pharmacokinetic (PK) parameters 2. pharmacodynamic (PD) efficacy measures * Generate a population PK model and determine dose level for later dosing groups * collect data to inform the design of a subsequent phase 2b/3 study of TTI-0102 in this patient population Participants will be asked to: * Take the study drug twice daily for 12 weeks * Visit the clinic for checkups and testing 7 times in total: once prior to study drug dosing, then 5 times over the 12-week treatment period and one more time a month after the last study drug dose.

The main goal of the project is provision of a global registry for mitochondrial disorders to harmonize previous national registries, enable world-wide participation and facilitate natural history studies, definition of outcome measures and conduction of clinical trials.

CoRDS, or the Coordination of Rare Diseases at Sanford, is based at Sanford Research in Sioux Falls, South Dakota. It provides researchers with a centralized, international patient registry for all rare diseases. This program allows patients and researchers to connect as easily as possible to help advance treatments and cures for rare diseases. The CoRDS team works with patient advocacy groups, individuals and researchers to help in the advancement of research in over 7,000 rare diseases. The registry is free for patients to enroll and researchers to access. Visit sanfordresearch.org/CoRDS to enroll.

The purpose of this study is to develop a database containing clinical and laboratory information for patients with Leigh syndrome. The goal is to provide a greater understanding of Leigh syndrome allowing further characterization of this disease.