IQSEC2 Mutation-Related Rett Syndrome

Introduction: Rett syndrome (RS) is a neurodevelopmental disorder characterised by speech regression, loss of acquired voluntary hand skills, and stereotypic hand movements and gait abnormalities. IQSEC2 mutation is an X-linked inherited gene that can cause X-linked semidominant disorders with different severity between males and females such as intellectual disability, epilepsy, autism, microcephaly,d stereotypic movement disorder etc. Material-Methods: Written informed consent was obtained from the patient and his guardian for the case report. Identity information was hidden due to patient privacy. Case Report: An 8-year-old male patient was followed for epilepsy and global developmental regression. In the medical history, neuromotor development was normal for the first 12 months, after which there was a loss of voluntary hand skills and a loss of language ability. Follow-up of the patient revealed gait impairment and Rett-like stereotypic hand movements. The brain MRI examination was normal. No abnormality was detected in the basic metabolic and genetic work up. IQSEC2 mutation was detected in the large epilepsy next-generation sequence analysis panel. Because of presence of all the main clinical criteria ,IQSEC2-related RS was diagnosed in the patient. Conclusion: RS is a clinical diagnosis, for which all the main criteria are required. IQSEC2 mutation should be considered in male patients presenting with clinical findings consistent with RS, and in whom common mutations such as MECP2, CDKL5, and FOXG1 are not detected.