A rare neurodegenerative disorder with a novel mutation in ROGDI and Rett- like phenotype: Kohlschütter- Tönz syndrome

ABSTRACT

@#Kohlschütter-Tönz syndrome (KTZS) is a rare neurodegenerative disorder that presents with seizures, developmental delay, psychomotor regression, hypoplastic dental enamel morphology characteristic for amelogenesis imperfecta, and dysmorphologies. Genetic analysis has identified loss of function mutations within the coding region of the ROGDI and SLC13A5 genes in KTZS. In this report, we documented the clinical, radiological, electroencephalographic, and genetic results of a 3.5-year-old Turkish girl, born to nonconsanguineous parents, who was the first patient diagnosed with KTZS in Turkey. The patient presented with Rett syndrome-like phenotype, neurodevelopmental delay, refractory seizures, and amelogenesis imperfecta. After obtaining informed consent, chromosomal DNAwas extracted from the peripheral blood of our patient and her parents. To investigate the moleculardiagnosis of the patient, the clinical exome sequencing was performed. The Sanger sequencing analysiswas performed for all of the family members for the validation and segregation of this mutation. PubMed/Medline, Web of Science, and Google Scholar were also searched to find all of the publisheddata on KTZS. The literature comprises 18 published studies about KTZS. The genetic analysis of ourpatient revealed a novel homozygous c.201-1G>T mutation in the ROGDI gene. The same mutationwas also found to be heterozygous in her mother and father. The mutation caused alternative splicingof the ROGDI translation and resulted in a disruption of the ROGDI protein.