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Patho chp 6
Term | Definition |
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allele | One of two or more different forms of a gene that can occupy a particular locus on a chromosome |
mosaicism | In genetics, the presence in an individual or in an organism of cell cultures having two or more cell lines that differ in genetic constitution but are derived from a single zygote |
aneuploidy | A variation in the number of chromosomes within a cell involving one or more missing chromosomes rather than entire sets |
homozygous | Having two identical alleles at corresponding loci on homologous chromosomes |
heterozygous | Having two different alleles at corresponding loci on homologous chromosomes |
Prenatal diagnosis | includes the use of ultrasonography, maternal blood screening, amniocentesis, chorionic villus sampling, and percutaneous umbilical fetal blood sampling |
Ultrasonography | used for determination of fetal size and position and for the presence of structural anomalies |
Maternal blood screening | measures α-fetoprotein (AFP), unconjugated estriol, and chorionic gonadotropin (hCG), is used to assess for neural tube defects (AFP) and Down syndrome (AFP, unconjugated estriol, and hCG) |
Amniocentesis | chorionic villus sampling, and percutaneous umbilical blood sampling are used to obtain specimens for cytogenetic and biochemical studies |