A Croatian girl with Rett syndrome and novel mutation on exon 4 – 25 bp deletion (c.881_905del25) of MECP2 gene.

Purpose: To present the genetic and clinical features of the girl with Rett syndrome, especially in regards to epilepsy. Rett syndrome is pervasive developmental disorder caused by mutations in the X-linked methyl-CpG-binding protein2 (MECP2) in majority of cases. It is predominantly found in females with normal development prior an onset of symptoms between 7-18 months of age, epilepsy is considered as major problem.
Methods: Retrospective review of data, electroencephalography and treatment was done in 19 years old girl previously diagnosed with MECP2 mutation.
Results: The girl was born in the healthy family, as a 4th child, after an uneventful pregnacy, delivery and perinatal period. Growth and psychomotor development were normal, excepte for delayed speech. First absence seizure occured at the age of 3 years during a bath. The EEG showed focal discharges and the therapy with CBZ was started. After frequent absances EEG showed generalised discharges and VPA was adder. At the age of 3,5 years autistic behaviour was observed followed by rapid mental deterioration, loss of speech and motor skills, with periods of hyperventilation and fear, rarely "hand-washing" movements appeared. After exclusion of wide spectrum of neurometabolic diseases, at the age of 5 years genetic analysis resulted in a mutation on exon 4 - 25bp deletion (c.881-905del25) of MECP2 gene. Till now multiple epileptic seizure types occured daily, refractory to all antiepileptic polytherapy with normal videoEEG background, sha is able to walk slowly on wide based gait, she is atactic and spastic.
Conclusion: In our girl onset of symptoms began much later than in usual cases of Rett syndome, epilepsy has daily fequency and drug resistance, unexpectedly she is able to walk at the age of 19 years. May be existes genotype-phenotype correlation.