Introduction:

the methyl-CpG binding protein 2 (MECP2) gene is located on chromosome Xq28; Rett syndrome (RS) occurs when there is a mutation in this gene. RS predominantly affects women; however, it can also occur in men.

Objective:

to describe the clinical characteristics of a male patient with RS.

Presentation of case:

seven-month-old male patient, who had seizures since birth. At four months he presented neurodevelopmental regression, choreodysonic movements, lack of head growth, dysautonomic symptoms and alterations in respiratory pattern, all of which were suggestive of progressive encephalopathy. Metabolic and infectious etiologies were ruled out. The genetic study revealed pathogenic variant c.806del (p.Gly269Alafs*20) in MECP2, confirming the diagnosis of SR. The patient continued to deteriorate until he died.

Conclusion:

RS in men has a more unfavorable prognosis than women, but the clinical characteristics are similar.