Cells shed by the developing fetus and found in the surrounding amniotic fluid. A procedure performed via the cervix between the 8th and 12th week of pregnancy to detect genetic defects in the fetus. Structure in a cell on which genes are located, consisting of a highly compacted stretch of DNA with associated proteins. Structural abnormalities include translocations, deletions or insertions, duplications and amplifications.
Numerical abnormalities are either a gain or loss of chromosomes.
One who studies human chromosomes and their abnormalities. An acronym for deoxyribonucleic acid. DNA contains all the information necessary for any organism to develop and function. The four chemical building blocks of DNA are Adenine, Thymine, Cytosine and Guanine. A segment of DNA specifically designed to be complementary to a target sequence of chromosomes, genes or gene sequences.