Kaya-Barakat-Masson syndrome (KABAMAS) is a severe autosomal recessive neurodevelopmental disorder characterized by profoundly impaired global development with variable motor abnormalities, such as axial hypotonia, peripheral spasticity, dystonia, and poor coordination, resulting in the inability to sit or walk. Affected individuals have impaired intellectual development with absent speech, poor eye contact, and feeding difficulties, resulting in poor overall growth, sometimes with microcephaly. Dysmorphic features are generally not present. Additional more variable features include early-onset seizures, ocular anomalies, foot deformities, and nonspecific brain imaging findings, such as thin corpus callosum and cerebral, cerebellar, or pontine atrophy. Some patients may die in infancy or early childhood (summary by AlMuhaizea et al., 2020 and Diaz et al., 2020). [from OMIM]