[MECP2 mutation in a male patient identified in the background of severe epileptic encephalopathy]. / Súlyos epilepsziás encephalopathia hátterében azonosított MECP2-gén-mutáció fiúbetegben.

Here we report on a severe, neonatal onset epileptic encephalopathy manifested in a currently 2-year-old boy with no family history of neurological disease. Extensive clinical investigations were unable to clarify the etiology of the infant's condition characterized by drug-resistant seizures and markedly delayed developmental skills. As in this class of disorders a genetic cause might be identified, a next-generation sequencing (NGS) epilepsy panel examination consisting of 128 genes was initiated for a correct diagnosis. The genetic analysis identified a previously undescribed hemizygous missense mutation in the MECP2 gene. Similarly to other, X-linked dominant disorders, Rett syndrome was originally hypothesized to be lethal in males. This theory, however, has been revised. The aim of this report is to review the wide spectrum of neurodevelopmental diseases observed in male patients carrying mutations in the MECP2 gene classically associated with Rett syndrome in girls. To the author's knowledge, this is the first report in Hungary to document MECP2 mutation of a male patient diagnosed by molecular genetic testing. Orv Hetil. 2019; 160(51): 2036-2039.