Down’s syndrome is a genetic disorder. It is caused by presence of an additional chromosome 21. Down syndrome occurs because of an abnormality characterized by an extra copy of genetic material on all or part of the 21st chromosome. Every cell in the body contains genes that are grouped along chromosomes in the cell's nucleus or center. There are normally 46 chromosomes in each cell, 23 inherited from your mother and 23 from your father. When some or all of a person's cells have an extra full or partial copy of chromosome 21, the result is Down's syndrome.
Karyotype for trisomy Down syndrome: Notice the three copies of chromosome 21
Usually they can be easily recognized by their distinct facial features like teddy bear like appearance, wide placed, slanted eyes, flat nose, short stature etc.
Most of chromosomal abnormality occurs in pregnancy where the maternal age is more. Kids with Down’s syndrome may suffer from congenital heart issues, hearing and speech difficulties, thyroid dysfunctions, slow physical growth leading to obesity.
Down’s syndrome can be detected through tests during 4th or 5th month of pregnancy or usually at time of birth. But in cases wherein the maternal age is more, doctors now-a-days usually suggest various tests in 1st 4 months of pregnancy to rule out any kind of abnormalities.
Kids with Down’s syndrome need regular follow-ups with their pediatric doctor and cardiologist to rule out any kind of problems and also therapies to develop their cognitive skills. Kids with Down’s syndrome need special schooling and vocational training.