Denis is 25 years old, but his development is like that of a three-year-old child. Denis has been a Group I disabled person since childhood and is legally incapacitated. He can hardly do anything on his own: take medicine, wash himself, or get dressed. Denis was born healthy and grew and developed according to his age. His first epileptic seizure occurred when he was three years old, after surgery under anesthesia. Denis's development stopped and regressed—he even forgot how to ride a bicycle. Since then, his parents have been searching for ways to help their son: they have taken him for examinations and tried many medications, but none have helped. Even the surgery to implant a vagus nerve stimulator, performed in 2022, did not help. Denis still suffers from seizures. Despite this, Denis is a kind guy. He loves going for walks, riding in the car with his dad, helping his mom, and playing with his brothers. He has two younger brothers: Andrey and Artyom. He loves them very much. Now, in order to find the cause of Denis's illness and choose a treatment, it is necessary to undergo genetic testing—an expensive exome sequencing analysis.