It is a disease caused by a gene problem in which a child with certain features is born with a flat face or short neck or some disability in the intellectual process. The disability, which may be mild or severe, may vary from person to person. The children with down syndrome had to be taken care of and this can enhance the children’s lives. The disease is very common, and it generally occurs when an individual has an extra copy of chromosome 21. This disease is of three types: trisomy 21 (nondisjunction), translocation and mosaicism. Though there are some screening and tests that can detect this disease earlier than the birth of a baby. Old women are more likely to give birth to a baby with down syndrome and patient of this disease are likely to have other diseases like Alzheimer and epilepsy.