Kohlschütter-Tönz Syndrome - Report of an additional case

Epileptic encephalopathy and amelogenesis imperfecta: What about KohlschüttereTönz syndrome? Case report and literature review

BACKGROUND

KohlschüttereTönz syndrome (KTS), also called amelo-cerebro-hypohidrotic syndrome, is a very rare genetic condition, described for the first time by Kohlschutter, which typically manifests as a triad of symptoms:  amelogenesis imperfecta, infantile onset epilepsy, and intellectual disability. 47 cases were reported in English language literature since 1974-2021.

CASE REPORT

A 7-year-old girl was referred for dental evaluation. Oral examination revealed yellowish color of all the teeth due to enamel hypoplasia. The radiographic exam revealed a thin layer of enamel with decreased radiopacity of the enamel compared to that of dentin. The diagnosis of amelogenesis Imperfecta was established. In addition to that, the child's parents reported that she had spasticity, epileptic seizures and psychomotor developmental delay. The association of all these features leads us to conclude to KTS.

CONCLUSION

It seems that numerous cases of KTS are still undiagnosed in the world, so this paper highlights the common clinical features of Kohlschütter-Tönz Syndrome helping to an early diagnosis and more research about this condition.

Kohlschütter-Tönz syndrome: Case report with novel feature and detailed review of features associated with ROGDI variants

Kohlschütter-Tönz syndrome (KTS) is a rare, autosomal recessive syndrome characterized by a triad of epilepsy, amelogenesis imperfecta and severe global developmental delay. It was first described in a Swiss family in 1974 by Alfried Kohlschütter and Otmar Tönz. It is caused by pathogenic variants in the ROGDI gene. To the best of our knowledge, there are currently 43 patients with a confirmed ROGDI gene pathogenic variant reported. Here, we review in detail the clinical manifestations of KTS, provide an overview of all reported genetically confirmed patients, and document an additional case of KTS-a 6-year-old Latvian girl-with a confirmed ROGDI gene pathogenic variant. In contrast to previous reports, we detected idiopathic bilateral nephrocalcinosis in this newly identified KTS patient. Perampanel proved an effective treatment for our patient with prolonged super-refractory status epilepticus. In order to better characterize this rare syndrome and its clinical course, it is important to report any additional symptoms and also the effectiveness of used therapies. Future research should focus on elucidating the mechanisms by which the absence/insufficiency of ROGDI-encoded protein causes the clinical manifestations of KTS. This knowledge could shape possible ways of influencing the disease's natural history with more effective therapies.

A Study of Enamel Defects and Dental Caries of Permanent Dentition in School Children with Intellectual Disability

Data concerning the prevalence of developmental enamel defects and their association with dental caries in individuals with intellectual disability are scarce. This paper aims to evaluate the prevalence and distribution of developmental enamel defects and dental caries in the permanent dentition of special-care school children from Poznan (Poland). Out of 1091 students attending all special-care schools in the city, the study covered 268 subjects with intellectual disability (mild, moderate, severe, and profound) with permanent dentition, aged 10-20. One calibrated dentist performed dental examinations. The Statistica Software v10 was used for statistical analysis, assuming the level of statistical significance p ≤ 0.05. Among the subjects of the study, 19.40% presented developmental enamel defects. The number of teeth with changes ranged from 1 to 28, with maxillary incisors most frequently affected. Students without developmental enamel defects had more teeth observed with active caries compared to those with such changes (10.92% vs. 7.82%, p < 0.01). The highest number of students with developmental defects of enamel was observed in the group of individuals with mild intellectual disabilities. The present study revealed that in special-care students from Poznan, enamel defects and dental caries were frequently observed. However, individuals with developmental enamel defects did not show higher dental caries indices.