[The Angelman's syndrome].

Distinction of patients with Angelman's syndrome in a group of mentally retarded patients is important even though the syndrome was rarely reported since the original description in 1965. Before that time these patients were thought to suffer from neurologic sequelae of perinatal asphyxia, Lennox-Gastaut syndrome or mental retardation of unknown origin. Diagnosis is based on the following criteria: developmental delay from early age, absent speech (or speech limited to less than six words), jerky movements with an ataxic gait if the patient is walking, paroxysm of inappropriate laughing, dysmorphic craniofacial features (brachycephaly, mid-facial hypoplasia, deep set eyes, macrostomia, prominent mandible). About 60% of patients have deletion of chromozome 15q11-13. Cytogenetic studies suggest that de novo deletion of chromozome 15 is connected with the low recurrence risk and that families with several members with Angelman's syndrome belong to the group without identifiable deletion on citogenetic or molecular level. The article deals with the diagnostic criteria, clinical features and electroencephalographic changes (after several years of followup) in seven children with Angelman's syndrome (four girls and three boys).