neurodevelopmental disorder with hypotonia and variable intellectual and behavioral abnormalities (MONDO_0032829) can be described as follows. Neurodevelopmental disorder in which the cause of the disease is a variation in the POLR2A gene; it is characterized by early-onset hypotonia, delayed walking, poor speech, and impaired intellectual development. Other features may include feeding difficulties, dysmorphic features, and visual problems. Brain magnetic resonance imaging tends to show delayed myelination, thin corpus callosum, and/or enlarged ventricles. Also known as: NEDHIB, POLR2A-Related Disorders, POLR2A-associated neurodevelopmental disability, POLR2A-related disorder.