Improved clinical outcome following liver transplant in patients with ethylmalonic encephalopathy.

Ethylmalonic encephalopathy (EE) is a rapidly progressive autosomal recessive mitochondrial disease caused by biallelic pathogenic variants in the ETHE1 gene that encodes the mitochondrial sulfur dioxygenase. It is characterized by neurodevelopmental delay and regression, pyramidal and extrapyramidal signs, recurrent petechiae, chronic diarrhea, and orthostatic acrocyanosis. Laboratory findings include elevated serum levels of lactate and C4-C5 acylcarnitines, and elevated urinary excretion of ethylmalonic acid and C4-C6 acylglycines, notably isobutyrylglycine and 2-methylbutyrylglycine. These findings are attributed to deficiency of the mitochondrial sulfur dioxygenase resulting in toxic accumulation of hydrogen sulfide metabolites in vascular endothelium and mucosal cells of the large intestine. Medical management has thus far been directed toward decreasing the accumulation of hydrogen sulfide metabolites using a combination of metronidazole and N-acetylcysteine. More recently, orthotopic liver transplant (OLT) has been reported as a new therapeutic option for EE. Here, we report two additional cases of EE who achieved psychomotor developmental improvement after 7- and 22-months following OLT. The second case serves as the longest developmental outcome follow-up reported, thus far, following OLT for EE. This report provides additional evidence to validate OLT as a promising therapeutic approach for what was considered to be a fatal disease.

Biallelic variants in COX4I1 associated with a novel phenotype resembling Leigh syndrome with developmental regression, intellectual disability, and seizures.

Autosomal recessive COX4I1 deficiency has been previously reported in a single individual with a homozygous pathogenic variant in COX4I1, who presented with short stature, poor weight gain, dysmorphic features, and features of Fanconi anemia. COX4I1 encodes subunit 4, isoform 1 of cytochrome c oxidase. Cytochrome c oxidase is a respiratory chain enzyme that plays an important role in mitochondrial electron transport and reduces molecular oxygen to water leading to the formation of ATP. Defective production of cytochrome c oxidase leads to a variable phenotypic spectrum ranging from isolated myopathy to Leigh syndrome. Here, we describe two siblings, born to consanguineous parents, who presented with encephalopathy, developmental regression, hypotonia, pathognomonic brain imaging findings resembling Leigh-syndrome, and a novel homozygous variant on COX4I1, expanding the known clinical phenotype associated with pathogenic variants in COX4I1.

Development of the Emirates Multi-Criteria Decision Analysis Tool for Orphan Drugs.

Background The number of orphan drug approvals is currently increasing globally. This creates a significant burden on payers and healthcare systems. This study aimed to create a multi-criteria decision analysis (MCDA) tool for evaluating orphan drugs within the United Arab Emirates (UAE). The intended result of the tool is to provide evidence-based guidance to decision-makers in reimbursement and procurement decisions. Methods We conducted a literature search and local expert interviews to identify relevant preliminary criteria for the MCDA tool. Then we conducted a structured consensus-building session for healthcare experts and decision-makers in the UAE to develop the Emirati MCDA tool for orphan drugs. The experts voted for the criteria to be included in the tool and their ranking according to importance, as well as the weight of each criterion and its scoring function. To improve understanding and facilitate the voting process, experts were provided with a brief illustration of similar tools conducted in other countries before the voting sessions. Finally, the tool was developed in a Microsoft Excel sheet (Microsoft Corporation, Redmond, Washington, United States), and it was validated and tested based on real case studies, then it was fine-tuned accordingly based on the experts' discussions. The final tool was provided to the attendees to guide their decisions in the reimbursement and procurement of orphan drugs. Results The created tool provides a score for each analyzed orphan drug based on its value. Ten criteria were included in the final MCDA tool. These were cost-effectiveness (25.1% of the weight), magnitude of health gain (20.1%), availability of therapeutic alternative (14.3%), disease severity (11%), budget impact (7.9%), disease rarity (5.6%), strength of clinical evidence (5.6%), burden on households (4.5%), indication uniqueness (3.2%), and patients' age (2.6%). Conclusions Implementation of evidence-based healthcare necessitates assessing the fair value of each health technology. Addressing the high unmet medical needs and improving healthcare for patients with rare diseases are priorities within the UAE. The created Emirates MCDA tool for orphan drugs has the potential to help decision-makers implement value-based and evidence-based reimbursement decisions for orphan drugs.