This is a 2 patient study aimed at studying the role of stem cell transplant in PGK deficiency. Because the disease is so rare, the study will be limited to the 2 sibling patients followed by our group, though it would be open to other participants who would meet inclusion/exclusion criteria if such presented to us. The objective of this study is to evaluate the feasibility and efficacy of stem cell transplants to treat patients with PGK deficiency, Amiens subtype.