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Triploid syndrome, also called triploidy, is a chromosomal disorder in which a fetus has three copies of every chromosome instead of the normal two. If this occurs in only some cells, it is called mosaic triploidy and is less severe. Most embryos with triploidy miscarry early in development.
Polyploidy is a condition in which the cells of an organism have more than two paired sets of chromosomes. Most species whose cells have nuclei ( eukaryotes ) are diploid , meaning they have two complete sets of chromosomes, one from each of two parents; each set contains the same number of chromosomes, and the chromosomes are joined in pairs ...
Diploid-triploid mosaicism is a human chromosome disorder.Individuals with diploid-triploid syndrome have some cells with three copies of each chromosome for a total of 69 chromosomes (called triploid cells) and some cells with the usual 2 copies of each chromosome for a total of 46 chromosomes (called diploid cells).
Triploid organisms, for instance, are usually sterile. Because of this, triploidy is commonly exploited in agriculture to produce seedless fruit such as bananas and watermelons. If the fertilization of human gametes results in three sets of chromosomes, the condition is called triploid syndrome. [citation needed]
Trisomy 21 – Down syndrome, an example of a polysomy at chromosome 21. Polysomy is a condition found in many species, including fungi, plants, insects, and mammals, in which an organism has at least one more chromosome than normal, i.e., there may be three or more copies of the chromosome rather than the expected two copies. [1]
Both the micrographic and schematic karyograms show the normal human diploid karyotype, which is the typical composition of the genome within a normal cell of the human body, and which contains 22 pairs of autosomal chromosomes and one pair of sex chromosomes (allosomes).
Most cells in the human body have 23 pairs of chromosomes, or a total of 46 chromosomes.(The sperm and egg, or gametes, each have 23 unpaired chromosomes, and red blood cells in bone marrow have a nucleus at first but those red blood cells that are active in blood lose their nucleus and thus they end up having no nucleus and therefore no chromosomes.) [8]
Karyotype of a human with Trisomy 21 (Down syndrome). Trisomies can occur with any chromosome, but often result in miscarriage rather than live birth.For example, Trisomy 16 is most common in human pregnancies, occurring in more than 1%, but the only surviving embryos are those having some normal cells in addition to the trisomic cells (mosaic trisomy 16). [3]