West syndrome in identical twins with white spots

West syndrome characterized by infantile spasms and hypsarrhythmia has many different etiologies. Apart from traumatic and hypoxic or inflammatory causes this epileptic encephalopathy is associated with some genetic syndromes. In tuberous sclerosis, characterized by multiple hamartous changes in different organs, West syndrome is prevalent in up to 55% of children at the susceptible age. We report on monozygotic twins born prematurely at 34 weeks of gestation. After an uneventful perinatal period they were admitted to hospital with gastroenteritis at the age of 3.5 months. During hospitalization opisthotonia and episodic nystagmus became evident in both children. Only a few days after admission both children developed typical infantile spasms. West syndrome was confirmed by hypsarrhythmia in the EEG in both patients with a time lag of a few days between the children. On the clinical examination the lack of visual attention, the paroxysmal nystagmus and the marked increase in muscle tone were most evident. Wood-light examination revealed multiple white spots. MRI and CT scans of the brain were completely normal as were sonography of kidneys and heart. Ophthalmological examination showed no retinal abnormalities. With the features West syndrome, white spots and a first grade family member with probable tuberous sclerosis (as the respective identical twin could be interpreted) the diagnosis of tuberous sclerosis was highly probable according to the modified criteria of Gomez. Molecular genetics however revealed no mutations of the TSC1- nor in the TSC2-gene. West syndrome in twins is a rare condition if there is no perinatal trauma. As both children had a proven identical genetic background and no secondary trauma, a genetic origin of this epileptic syndrome is highly suggestive. A candidate gene might be the ARX gene, responsible for some cases of x-linked infantile spasms without associated anomalies of genitalia and brain.