Diagnosis of Angelman Syndrome, With 66 Years of Delay, Using Hypothesis-Free DNA Methylation Profiling.

Hypothesis-free DNA methylation profiling in a 66-year-old male with unexplained neurodevelopmental disorder enabled the exclusion of ZNF142-related disease (left panel) and led to a retrospective diagnosis of Angelman syndrome, highlighting the diagnostic potential of single-patient epigenetic screening (right panel).