Child Development Disorders, PervasiveAutistic DisorderAsperger SyndromeSocial BehaviorLanguage Development DisordersRegression (Psychology)Stereotyped BehaviorStereotypic Movement DisorderDevelopmental DisabilitiesCommunication DisordersEarly DiagnosisIntellectual DisabilityTheory of MindSiblingsMagnetic Resonance ImagingPlay and PlaythingsIntelligenceCase-Control StudiesBrainHealth Planning CouncilsVerbal BehaviorEarly Intervention (Education)Nonverbal CommunicationEndophenotypesIntelligence TestsLanguage TestsSocial PerceptionSocial Behavior DisordersDelayed DiagnosisSensitivity and SpecificityNeuropsychological TestsInterpersonal RelationsLanguage DevelopmentPrenatal DiagnosisGenetic Predisposition to DiseaseLanguage DisordersChild DevelopmentParentsImitative BehaviorFragile X SyndromeAttention Deficit Disorder with HyperactivityFaceFacial ExpressionCommunicationMacrocephalyPhenotypeAttentionDNA Copy Number VariationsChild BehaviorChild LanguageCompulsive BehaviorReproducibility of ResultsPsychiatric Status Rating ScalesSeverity of Illness IndexLanguage TherapyRett SyndromeRetrospective StudiesPsychological TestsLanguageBrain MappingAge FactorsChild PsychiatryInfant BehaviorNeural PathwaysCognitionEducation, SpecialWechsler ScalesRisk FactorsDiagnosisPersonality AssessmentMethyl-CpG-Binding Protein 2Cell Adhesion Molecules, NeuronalGroomingBehavior TherapyCohort StudiesAnalysis of VarianceTime FactorsImage Processing, Computer-AssistedIrritable MoodPregnancySpeechMutationSibling RelationsPersonal Construct TheoryInfant, NewbornQuestionnairesComorbidityEye Movement MeasurementsDiagnostic and Statistical Manual of Mental DisordersGenetic Association StudiesPerceptual DisordersTreatment OutcomeNerve Tissue ProteinsSensation DisordersChild Behavior DisordersPrevalencePattern Recognition, VisualPedigreeAptitudePhotic Stimulation