TrisomyChromosomesChromosome MappingDown SyndromeChromosome BandingChromosome AberrationsChromosomes, Human, Pair 21X ChromosomeKaryotypingChromosomes, Human, Pair 18Chromosome DisordersChromosomes, Human, Pair 13Chromosomes, Human, 16-18Chromosomes, Human, 6-12 and XSex ChromosomesChromosomes, Human, Pair 1Chromosomes, Human, Pair 7Chromosomes, HumanChromosomes, Human, Pair 11Chromosomes, Human, 13-15Chromosomes, Human, Pair 17Chromosomes, BacterialChromosomes, Human, Pair 9Chromosome SegregationChromosome DeletionChromosomes, Human, Pair 8Chromosomes, Human, Pair 6Chromosomes, Human, Pair 12Chromosomes, Human, 21-22 and YIn Situ Hybridization, FluorescenceChromosomes, Human, Pair 16Chromosomes, Human, 1-3Chromosomes, Human, Pair 22Chromosomes, Human, Pair 10Chromosomes, Human, Pair 2Chromosomes, PlantChromosomes, FungalChromosomes, Human, Pair 4MosaicismChromosomes, Human, Pair 5Chromosomes, MammalianChromosomes, Human, Pair 19Abnormalities, MultipleChromosome PairingChromosomes, Human, Pair 15Chromosomes, Human, YChromosomes, Human, 4-5Chromosomes, Human, XNondisjunction, GeneticChromosomes, Human, Pair 20AneuploidyChromosomes, Human, Pair 14Prenatal DiagnosisChromosomes, Artificial, BacterialTranslocation, GeneticChromosome PaintingChromosomes, Human, 19-20Chromosome InversionGenetic MarkersChromosomes, Artificial, YeastGenetic LinkageChromosome BreakageRing ChromosomesNuchal Translucency MeasurementChorionic Gonadotropin, beta Subunit, HumanChromosome PositioningMaternal AgePregnancy Trimester, FirstMeiosisPregnancyMonosomyUltrasonography, PrenatalMolecular Sequence DataFetal DiseasesX Chromosome InactivationBase SequencePedigreeCentromerePhenotypeMetaphasePregnancy Trimester, SecondPregnancy-Associated Plasma Protein-ANasal BoneChromosomes, InsectHybrid CellsAmniocentesisDermatoglyphicsMitosisChromosome StructuresRecombination, GeneticMicrosatellite RepeatsPregnancy, High-RiskMutationCytogenetic AnalysisCytogeneticsIntellectual DisabilityAllelesLod ScoreCrown-Rump LengthCrosses, Genetic