Description

Down syndrome is a genetic disorder with abnormality in number of chromosomes where extra genetic material from chromosome 21 transferred to a newly formed embryo having 47 chromosomes in their cells instead of 46 normal number of chromosomes. Hence it is also known as trisomy 21. In every cell in the human body there is a nucleus, where genetic material is stored in genes. genes carry the codes responsible for all of our inherited traits and are grouped along rod like structures called chromosome. Typically, the nucleus of each cell contains 23 pairs of chromosomes, half of which are inherited from each parent. Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21. This additional genetic material alters the course of development and causes the characteristics associated with down syndrome. The main cause, women who are 35 years or older when they become pregnant are more likely to have a pregnancy altered by down syndrome then women who become pregnant at younger age. However, the majority of babies with down syndrome are born to mothers less than 35 years old because there are many more births among young women.