Epileptic encephalopathy and amelogenesis imperfecta: Kohlschütter-Tönz syndrome.

Kohlschütter-Tönz syndrome is a rare genetic disorder with epilepsy, psychomotor regression, and a severe enamel defect with yellow or brownish discoloration of the teeth. The first affected family was described in 1974, and 25 patients in 11 families have been reported until now. Inheritance is autosomal recessive. Epilepsy usually starts within the first or second year of life. All affected individuals show a psychomotor regression after onset of epilepsy or a developmental delay from birth on. Clinical course and disease severity are variable even within families. There are no known biochemical or other diagnostic markers of the condition. Very recently it has been shown that the condition is caused by mutations in the gene ROGDI but molecular data have only been reported for three families. It remains to be seen whether Kohlschütter-Tönz syndrome has the same molecular basis in all affected individuals.