Ring chromosome 9 syndrome is an autosomal anomaly characterized by variable clinical features, most commonly including developmental delay, some degree of intellectual disability, facial dysmorphism, microcephaly, congenital heart anomalies, and variable genital, limb and skeletal anomalies.

Seizures are an intermittent abnormality of the central nervous system due to a sudden, excessive, disorderly discharge of cerebral neurons and characterized clinically by some combination of disturbance of sensation, loss of consciousness, impairment of psychic function, or convulsive movements. The term epilepsy is used to describe chronic, recurrent seizures.