Rett syndrome: A classic presentation

We report a 3-year-old girl with characteristic clinical, electroencephalographic and neuroradiological features of Rett syndrome (RS) - an X-linked dominant, neurodevelopmental disorder caused by mutation in methyl-CpG binding protein 2 (MECP2) gene. It predominantly affects females and is one of the commonest causes of mental retardation in females. It is characterized by progressive loss of intellectual functioning, fine and gross motor skills and communicative abilities, deceleration of head growth, and the development of stereotypic hand movements, occurring after a period of normal development. A 3-year-old girl was brought from our neighboring country with progressive loss of milestones. She had a normal development till one year of age when she gradually lost her motor milestones and started socially withdrawing from her surroundings. She also started excessive hand playing which were stereotypical and repetitive. She was microcephalic and had marked postural hypotonia. Her electroencephalography and magnetic resonance imaging showed the characteristic change associated with RS. These clinical features support the diagnosis of RS even though genetic analysis was not done. This is the first case report of RS from Pakistan.