Angel syndrome, also known as Angelman syndrome and Happy Puppet syndrome, is a neurodevelopmental disorder caused by a genetic abnormality. Its early symptoms are usually normal in the perinatal period as well as usually normal at birth, with normal head circumference and no obvious birth defects, but there may be feeding difficulties in neonates and infants, significant developmental delays from 6-12 months of age, erratic limb movements, a marked increase in smiling or bursting into laughter, and developmental delays, but with progress and no skill deficits. Children tend to be hyperactive, ataxic, may have sleep disturbances as well as anxiety, and are autistic.Seizures occur in 80%-95% of children, and fever is the main trigger for seizures in most cases.Diagnosis can be made by MRI or CT, and genetic testing is now a popular diagnostic measure, and can now be diagnosed in 85%-90% of cases by genetics genetic testing methods.