Multisystem involvement in Chinese patients with neuromyopathic phenotype of mitochondrial trifunctional protein deficiency

摘要

Mitochondrial trifunctional protein (MTP) is a multienzyme complex, which catalyzes the last three steps of mitochondrial β-oxidation of the long-chain fatty acids. Structurally, MTP consists of four α-subunits and four β-subunits, which are encoded by gene (OMIM 600890) and gene (OMIM 143450), respectively. Mutations in or lead to varying degrees of decline in MTP activity, that in turn results in three types of clinical manifestations: a severe phenotype with neonatal onset, a hepatic phenotype with infantile onset, and a neuromyopathic phenotype with later onset. The neuromyopathic type is the mildest one, characterized by myopathy, sensorimotor neuropathy, and recurrent rhabdomyolysis. To the best of our knowledge, only 33 cases have been reported worldwide to date, of which there were only two cases (including Patient 3 of this study) in China. Here, we described three early-onset Chinese cases that not only showed neuromyopathy and rhabdomyolysis but also involved the central nervous system (CNS), which are uncommon in this phenotype.