What are the major human chromosome abnormalities?
Page 309 of textbook: “Approximately 15 percent of all recognized pregnancies in human beings terminate in spontaneous abortion, and in about half of all spontaneous abortions, the fetus has a major chromosome abnormality.” Table 8.2 shows what these chromosomal abnormalities are, and how often they show up in fetuses that abort or proceed to live birth. “Polyploidy” occurs in about 1 to 2% of human fetuses, but no polyploid babies ever make it to birth. In general, polyploidy is essentially never seen in vertebrates. Among animals as a whole, polyploidy is seen in some insects. (Textbook, page 311: “For example, in Drosophila, triploid females are viable, fertile, and nearly normal in morphology.”) Among plants, polyploidy is quite common, being the actual case for about 1/3 of all flowering plants, as well as for such cultivated plants as bananas, oats, cotton, potatoes, coffee, sugar cane, and wheat (Textbook pages 329-336). “Aneuploidy” (diploid chromosome number other than the nor
