Kohlschütter-Tönz syndrome in siblings without ROGDI mutation.

BACKGROUND: Kohlschutter-Tonz syndrome is a rare neurodegenerative disorder presenting with intractable seizures, developmental regression, and characteristic hypoplastic dental enamel indicative of amelogenesis imperfecta. Recently, mutations in ROGDI were identified in part of Kohlschutter-Tonz syndrome cases, but the siblings reported here do not have a mutation in the ROGDI gene, showing that there is genetic heterogeneity in Kohlschutter-Tonz syndrome. AIM: Report two siblings that have Kohlschutter-Tonz syndrome. CONCLUSION: Early onset of seizures and lack of the ability to walk without support may be signs of non-ROGDI mutations in Kohlschutter-Tonz syndrome patients.