Expanded Access (EA) will provide a transition to continue therapy for those patients who are currently in the open label extension of the Phase III study, SL 1009-01, while also allowing new patients diagnosed with PDCD who meet the eligibility criteria to also have access to therapy that would be otherwise unavailable.

Expanded Access (EA) will provide a transition to continue therapy for those patients who are currently in the open label extension of the Phase III study, SL 1009-01, while also allowing new patients diagnosed with PDCD who meet the eligibility criteria to also have access to therapy that would be otherwise unavailable. The Expanded Access program (EAP) will also allow the sponsor to extend the collection of long term safety data for the current open label patients, while also expanding to an additional population of patients beyond those currently in the SL 1009-01 study.

Inclusion Criteria:

1. Ages 0 through adulthood
2. Presence of characteristic clinical or metabolic features of PDCD and
3. Presence of a known pathogenic mutation of a gene that is specifically associated with PDC (PDHA1, PDHB, DLAT, PDHX, DLD).
4. Females of reproductive age must be willing to use an effective method of barrier contraception for the duration of the study.-

Exclusion Criteria:

1. A genetic mitochondrial disease other than those stipulated under inclusion criteria
2. Primary, defined organic acidurias other than lactic acidosis (e.g., propionic aciduria)
3. Primary disorders of amino acid metabolism
4. Primary disorders of fatty acid oxidation
5. Secondary lactic acidosis due to impaired oxygenation or circulation (e.g., due to severe cardiomyopathy or congenital heart defects)
6. Malabsorption syndromes associated with D-lactic acidosis
7. Renal insufficiency, defined as 1) a requirement for chronic dialysis or 2) serum creatinine ≥ 1.2 mg/dl or creatinine clearance <60 ml/min
8. Primary hepatic disease unrelated to PDCD
9. Pregnancy or breast feeding -