developmental delay and seizures with or without movement abnormalities

A syndromic intellectual disability characterized by global developmental delay, variable intellectual disability, and early-onset seizures with a myoclonic component that has_material_basis_in heterozygous mutation in the DHDDS gene on chromosome 1p36.

Signs and symptoms

• Epileptic encephalopathy
• Global developmental delay
• Tremor
• Generalized myoclonic seizure
• Bradykinesia
• EEG abnormality
• Delayed speech and language development
• Dystonia
• Rigidity
• Ataxia