Down syndrome is a chromosomal disorder in which a person is born with an extra chromosome. Chromosomes are the body's small "packages" of genes. They shape and function a baby's body as it develops during pregnancy and after birth. A baby is born with 46 chromosomes on average. One of these chromosomes, chromosome 21, has an extra copy in Down syndrome babies. Trisomy is a medical term for having an extra copy of a chromosome. Trisomy 21 is another name for Down syndrome. This extra copy alters the way the baby's body and brain develop, posing mental and physical challenges for the child.
WHAT CAUSES DOWN SYNDROME?
Both parents' genes are passed down to their children in every case of reproduction. Chromosomes are where these genes are stored. Each cell in the baby's body is supposed to receive 23 pairs of chromosomes, for a total of 46 chromosomes. The mother contributes half of the chromosomes, while the father contributes the other half. Down syndrome is caused by chromosome 21 having three copies of the genes instead of the usual two. The affected person's parents are typically genetically normal.
One of the chromosomes in children with Down syndrome does not separate properly. Instead of two copies of chromosome 21, the baby has three copies, or an extra partial copy. As the brain and physical features develop, this extra chromosome causes problems.
TYPES OF DOWN SYNDROME:
Down syndrome is divided into three categories. Because the physical features and behaviours of each type are so similar, people often can't tell the difference without looking at the chromosomes.
TRISOMY 21:Trisomy 21 affects approximately 95% of people with Down syndrome. Instead of the usual two copies of chromosome 21, each cell in the body has three copies of chromosome 21 in this type of Down syndrome.
TRANSLOCATION DOWN SYNDROME: A small percentage of people with Down syndrome have this type (about 3 percent ). When an extra part or a whole extra chromosome 21 is present, but it is attached or "trans-located" to another chromosome rather than being a separate chromosome 21, this occurs.
MOSAIC DOWN SYNDROME: Around 2% of people with Down syndrome have this type. Mosaic is a term that refers to a mixture or combination of things. Some of the cells in children with mosaic Down syndrome have three copies of chromosome 21, while others have the typical two copies. Children with mosaic Down syndrome may have the same characteristics as other Down syndrome children. Due to the presence of some (or many) cells with a typical number of chromosomes, they may have fewer symptoms of the condition.
Down syndrome is a chronic illness that lasts a lifetime. Early intervention can often aid babies and children with Down syndrome in improving their physical and cognitive abilities. The majority of these services are geared toward assisting children with Down syndrome in reaching their full potential. Speech, occupational, and physical therapy are examples of these services, which are typically provided through early intervention programmes in each state. Although many children with Down syndrome are included in regular classes, they may require additional help or attention at school.
Many people with Down syndrome have the same facial features as the general population and no other major birth defects. Some people with Down syndrome, however, may have one or more major birth defects or medical issues. People born with Down syndrome may have a variety of health issues, including heart defects or digestive abnormalities, as well as short stature and a single deep crease across the palm.