Genetic Approach to the Patient and the Family: A Rett Syndrome Case with R270X Mutation in MECP2 Gene

Rett syndrome is an X-linked dominant neurodevelopmental disorder which is primarily seen in girls. Mutations in the MECP2 gene are responsible for 80% of affected patients. The most common mutations are found in exons 3, 4 of this gene. Most MECP2 alterations are de novo and the recurrence risk is low. Approximately 1% of all affected patients are thought to be familial and clinically unaffected carrier mothers have been reported. Here, we present 3 year old girl patient who had all of the diagnostic criteria for typical Rett syndrome. The de novo, heterozygous c.808C>T mutation was detected by sequence analysis of exon 3 in the MECP2 gene. We report this patient to emphasize the importance of the steps followed in the molecular analysis in Rett syndrome. Hovewer, when the mutation was detected in a patient, the molecular analysis of the mother is extremely important for correct genetic counseling.