title: Commentary.
authors.affiliation: Division of Genetics, Boston Children's Hospital, Harvard Medical School, Boston, MA. wen-hann.tan@childrens.harvard.edu.
authors.forename: Wen-Hann
authors.initials: WH
authors.lastname: Tan
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*