The term PEHO syndrome is an abbreviation from the first letters of the most important symptoms: progressive encephalopathy, edema - in particular of the face and extremities, hypsarrhythmia and atrophy of the optic nerve. The authors demonstrate case-records of two female patients who meet the criteria of PEHO syndrome, whereby in one patient adenylsuccinate lyase deficiency was confirmed. In the second case the authors draw attention to the long-term therapeutic effect of felbamate in refractory epilepsy which is associated with the disease in the majority of cases.

        Key words: PEHO syndrome, progressive encephalopathy, adenylsuccinate lyase