Down condition or Down's condition, otherwise called trisomy 21, is a hereditary issue brought about by the nearness of all or part of a third duplicate of chromosome . It is normally connected with physical development delays, mellow to direct learned handicap, and trademark facial highlights. The normal IQ of a youthful grown-up with Down condition is 50, proportionate to the psychological capacity of a 8-or 9-year-old youngster, yet this can fluctuate widely.The guardians of the influenced individual are generally hereditarily normal.The likelihood increments from under 0.1% in 20-year-old moms to 3% in those old enough 45.The additional chromosome is accepted to happen by some coincidence, with no known social action or natural factor that changes the likelihood. Down disorder can be recognized during pregnancy by pre-birth screening followed by demonstrative testing or after birth by direct perception and hereditary testing. Since the presentation of screening, pregnancies with the finding are frequently ended. Customary screening for medical issues regular in Down disorder is suggested all through the individual's life.