Case report: Early-onset parkinsonism among the neurological features in children with variants.

is expressed in cardiovascular and neurological tissues. In the brain, it has a role in pre- and post-natal maturation. Previously reported -mutated patients showed early-onset epilepsy and intellectual disability. We describe two unreported cases with pathogenic variants in and their clinical pictures, compared with those of cases already reported in the literature. In line with previous reports, the two patients presented early-onset developmental and epileptic encephalopathy. In addition, one patient developed a speech disorder and a progressive movement disorder characterized by hypertonus, hypo-bradykinesia, hypomimia, ataxic gait, and retropulsion. She was treated with levodopa without any clinical improvement. Pathogenic variants in may result in a cardiological or neurological phenotype. Severe developmental delay, intellectual disability, and early-onset developmental and epileptic encephalopathy are the main features of -mutated patients with neurological involvement. Movement and speech disorders have never previously been described and could be new features of the neurological phenotype.