Symptoms vary according to the abnormality, but often feature poor muscle tone and motor function, seizures, developmental delays, intellectual disabilities, failure to grow and thrive, difficulties with feeding, swelling in the extremities, and a smaller than normal head.

Neuronal migration, which occurs as early as the second month of gestation, is controlled by a complex assortment of chemical guides and signals.

Defects in genes that are involved in neuronal migration have been associated with NMDs, but the role they play in the development of these disorders is not yet well understood.

[5] Treatment is symptomatic and may include anti-seizure medication and special or supplemental education consisting of physical, occupational and speech therapies.

[2] The prognosis for children with NMDs varies depending on the specific disorder and the degree of brain abnormality and subsequent neurological signs and symptoms.