title: Commentary.
authors.affiliation: Departments of Psychiatry & Behavioral Sciences and Pediatrics, University of Kansas Medical Center, Kansas City, KS. mbutler4@kumc.edu.
authors.forename: Merlin G
authors.initials: MG
authors.lastname: Butler
mesh_terms: D017204:Angelman Syndrome / Q000235:genetics*; D004252:DNA Mutational Analysis / Q000379:methods*; D006130:Growth Disorders / Q000235:genetics*; D006801:Humans; D008297:Male; D009123:Muscle Hypotonia / Q000235:genetics*; D011218:Prader-Willi Syndrome / Q000235:genetics*