LAUSR

Biallelic variants in the MTFMT gene have been associated with Leigh syndrome (LS) and mitochondrial multiple respiratory chain deficiencies, or a separate entity of MTFMT-related mitochondrial disease. More than 80 genes have been associated with LS with variable presentations; MTFMT variants are associated with a milder form. LS attributed to a methionyl-tRNA formyl transferase MTFMT gene mutation was found by Tucker and colleagues in 2011. Mitochondrial disorders are associated with a variety of movement disorders, such as dystonia, ataxia, myoclonus, spasticity, parkinsonism, tremor, tics, and restless leg syndrome. MTFMT gene variant– associated LS may present with various movement disorders and neurological symptoms. We document a case report of the MTFMT gene variant showing a milder form of LS, or rather MTFMT gene-related mitochondrial disorder with nonprogressive mobile dystonia and abnormal gait with a choreoathetosis-like presentation. Sustained muscle contractions in dystonia can cause repetitive twisting movements (“mobile” dystonia) or abnormal gait. Dystonic movements can be distinguished from chorea by their nonflowing characteristics along with increased tone. Dystonic movements may resemble myoclonus if they are fast, which has been termed amyoclonic dystonia. On the other hand, if they are slow, they resemble athetosis. Mobile dystonia is found in dyskinetic cerebral palsy involving the basal ganglia.