Rett syndrome (RTT) is an X-linked dominant neurodevelopmental disorder that occurs mostly in females. De novo mutations in the MECP2 gene have an important role in the appearance of the features of this syndrome. We planned to study spectrum of MECP2 mutations in Rett syndrome patients and their clinical symptoms. A cohort of 29 patients referred by neurologists from Iranian Azeri Turks was screened. Then direct sequencing was utilized to characterize the spectrum of mutations in the MECP2 gene in RTT patients. A total of 10 different mutations on MECP2 gene were detected in 22 patients. We identified 2 (9%) frameshift, 10 (45.64%) nonsense, 8 (36.4%) missense mutations, and 2(9%) large deletions. In this cohort, one of the detected deletions was novel, namely 1023-1096del74nt. Random X chromosome inactivation in females’ cells and different MECP2 mutations can cause a phenotypic variability between patients. This is the first report regarding the spectrum of MECP2 mutation and phenotypic spectrum in Iranian Azeri Turks with Rett syndrome. Our finding confirms a high mutation frequency (75.8%) of MECP2 gene in Iranian RTT patients.
