Angelman SyndromePrader-Willi SyndromeChromosomes, Human, Pair 15snRNP Core ProteinsGenomic ImprintingSyndromeUbiquitin-Protein LigasesUniparental DisomyLaughterRibonucleoproteins, Small NuclearChromosome DeletionIntellectual DisabilityMicrocephalyDNA MethylationIn Situ Hybridization, FluorescenceChromosome BreakagePedigreeAtaxiaChromosome MappingPhenotypeAbnormalities, MultipleGenetic CounselingChromosome BandingAutoantigensMethyl-CpG-Binding Protein 2FathersGenetic Markers