Central nervous system-targeted adeno-associated virus gene therapy in methylmalonic acidemia

Gene therapy for organic acidemias: Lessons learned from methylmalonic and propionic acidemia

Organic acidemias (OA) are a group of rare autosomal recessive disorders of intermediary metabolism that result in a systemic elevation of organic acid. Despite optimal dietary and cofactor therapy, OA patients still suffer from potentially lethal metabolic instability and experience long-term multisystemic complications. Severely affected patients can benefit from elective liver transplantation, which restores hepatic enzymatic activity, improves metabolic stability, and provides the theoretical basis for the pursuit of gene therapy as a new treatment for patients. Because of the poor outcomes reported in those with OA, especially methylmalonic and propionic acidemia, multiple gene therapy approaches have been explored in relevant animal models. Here, we review the results of gene therapy experiments performed using MMA and PA mouse models to illustrate experimental paradigms that could be applicable for all forms of OA.

Treatment of metabolic disorders using genomic technologies: Lessons from methylmalonic acidemia

Hereditary methylmalonic acidemia (MMA) caused by deficiency of the enzyme methylmalonyl-CoA mutase (MMUT) is a relatively common and severe organic acidemia. The recalcitrant nature of the condition to conventional dietary and medical management has led to the use of elective liver and combined liver-kidney transplantation in some patients. However, liver transplantation is intrinsically limited by organ availability, the risks of surgery, procedural and life-long management costs, transplant comorbidities, and a remaining underlying risk of complications related to MMA despite transplantation. Here, we review pre-clinical studies that present alternative approaches to solid organ transplantation as a treatment for MMUT MMA, including adeno-associated viral gene addition therapy, mRNA therapy, and genome editing, with and without nuclease enhancement.

Recent research on inherited metabolic diseases in children

With the improvement in the research level and the diagnosis and treatment technology of inherited metabolic diseases (IMD), the research on pediatric IMD in China has made great progress, but there is still some distance from the international level. Due to the vast territory of China and the uneven distribution of medical resources, the regional characteristics of IMD remain unclear in China, and there are many problems and difficulties in early diagnosis and treatment. Therefore, it is necessary to improve the understanding of pediatric IMD among pediatricians, so as to improve the diagnosis and treatment level, achieve an early identification, diagnosis, and treatment of pediatric IMD, and effectively reduce the fatality and disability rates of children with IMD. This article reviews the research progress of IMD in children in China, and analyzes the features of representative IMDs. Citation:Chinese Journal of Contemporary Pediatrics, 2022, 24(3): 326-331.