What are different types of trisomy?

trisomy is a genetic state in which cells have extra chromosome. Each cell usually carries 23 pairs of chromosomes. In conception, when the cells begin to divide, another chromosome can connect to a pair of chromosomes. This creates cells with 47 chromosomes rather than 46. Extra chromosome is usually expressed by significant physical and mental characteristics.

Complete trisomia occurs when each cell has another chromosome in the body. In mood trisomi, only some cells contain extra chromosome. People with partial trisomias have only part of the extra chromosome in their cells. Both mosaic and partial trisomy can be hereditary, while full trisomy is not. Trisomy is not caused by environmental or parental factors.

trisomy is numbered according to the location of the extra chromosome. There are 23 chromosome locations. Trisomy 21 or Down Syndrome means that there are three chromosomes in the locality of 21 ST . As with all trisomy, the risk of Down syndrome increases with the age of the mother in d dBoth births. A 45 -year -old woman has a chance of 1 out of 30 that she gives birth to a child of downy syndrome. It occurs in 1 out of 3,000 live birth. Edwards syndrome is usually fatal, with less than 10 percent of children born with this syndrome living for more than one year. The syndrome causes heart defects, kidney abnormalities and serious developmental delays.

Patau syndrome is the result of extra chromosome in position 13 ^{th or trisomy 13. Like Edwards syndrome, less than 10 percent of children born by Patau have been living for more than one year. This syndrome occurs in 1 in 10,000 live births. Může způsobit strukturální problémy s mozkem, těžkou mentální retardací a srdečními vadami.}

trisomy can occur on any of the other 20 chromosomes, but rarely results in a live birth. There are isolated cases of children with more rare trisomia surviving for several years. Trisomy 16 occursIn one percent of all pregnancies, but pregnancy usually lead to abortions during the first trimester.

Diagnosis usually occurs during pregnancy. The ultrasonic test can detect the heart or kidney problems of the child, and an amniocentesis procedure is then used to confirm the diagnosis. In the case of birth, a preliminary diagnosis may be made by a physician based on significant physical characteristics. Chromosomal analysis called kerotype is used to insulate chromosomes and confirmation of diagnosis.