Down SyndromeSyndromePoint MutationMutation, MissenseMutationChromosomes, Human, Pair 21Prenatal DiagnosisFrameshift MutationTrisomyGerm-Line MutationPedigreeMaternal AgeMetabolic Syndrome XEstriolPregnancy Trimester, SecondPregnancyBase SequenceExonsMolecular Sequence DataHeterozygoteAmniocentesisPhenotypeDNA Mutational AnalysisMutation RatePolymerase Chain ReactionLeukemia, Megakaryoblastic, AcuteAbnormalities, MultipleAllelesIntellectual DisabilityGenetic TestingFetal DiseasesNephrotic SyndromeGenotypeInfant, NewbornAmino Acid SubstitutionChromosomes, Human, 21-22 and YAbortion, EugenicAmino Acid SequenceKaryotypingSjogren's SyndromeHomozygoteTurner SyndromePolymorphism, Single-Stranded ConformationalSequence Analysis, DNAalpha-FetoproteinsCodon, NonsenseChromosome MappingMutagenesis, Site-DirectedGenes, RecessiveDisease Models, AnimalNasal BoneNondisjunction, GeneticNuchal Translucency MeasurementMutagenesisUltrasonography, PrenatalCase-Control StudiesCell LinePregnancy, High-RiskMyelodysplastic SyndromesPregnancy Trimester, FirstDNA PrimersWilliams SyndromeGenes, DominantProtein Structure, TertiarySequence DeletionDNA-Binding ProteinsCraniofacial AbnormalitiesMosaicismHeart Defects, CongenitalGenetic Predisposition to DiseaseLong QT SyndromeDNAPregnancy-Associated Plasma Protein-AChorionic Gonadotropin, beta Subunit, HumanPaternal AgeTranscription FactorsGene DeletionCushing SyndromeChromosome DisordersFalse Positive ReactionsSequence Homology, Amino AcidGenetic LinkageConsanguinityEscherichia coliRisk FactorsPolycystic Ovary SyndromeBinding SitesAcute Coronary SyndromeProtein BindingBrainPolymorphism, GeneticGene DosageCloning, MolecularTime FactorsMembrane ProteinsSuppression, GeneticModels, MolecularEye AbnormalitiesNuclear ProteinsDiGeorge Syndrome