Behaviour problems in Angelman syndrome.

English et al. (1995) asked parents of the children with Angelman syndrome to list every behavior problem they saw. The team also watched the kids during clinic visits. They wrote down what happened and how often.

No one had mapped the full behavior picture for this rare syndrome before. The goal was to give clinicians a first checklist.

Every child showed hyperactivity. Most had sudden laughing fits and hand-flapping. Sleep trouble, mouthing objects, and short attention spans were also common.

The authors noted that the problems looked the same no matter the child’s exact genetic change.

Leader et al. (2022) later asked the families the same kinds of questions. They found the same behaviors plus strong links to tummy pain and poor sleep. This larger survey turns the 1995 list into a red-flag triad: check behavior, GI, and sleep together.

Mertz et al. (2014) split kids by genotype. Deletion cases had lower developmental scores and more severe language delay than non-deletion cases. This finding updates the 1995 claim that "all kids look alike" by showing that genetic subtype predicts how deep the delays go.

Vassos et al. (2023) zoomed in on anxiety. Aggression and fear of caregiver separation topped the list. Their focused sample of the kids extends the 1995 catalog by telling you what to probe when you see sudden hitting or clinginess.

Use the 1995 checklist as your first screen, then layer on the newer data. Ask about stomach pain and sleep right after you see hyperactivity or laughter bursts. If the child has a 15q deletion, plan for slower receptive language gains and add visual supports early. When aggression pops up, test for caregiver-separation contexts before you write a behavior plan. These quick add-ons turn an old list into a modern, targeted assessment.