When a baby is born, each cell in his or her body contains 23 pairs of chromosomes or 46 chromosomes in total, with half coming from each parent. At least, this is the case most of the time.
Yet, the biological machinery responsible for assuring proper chromosome distribution sometimes goes awry. This can result in a range of serious genetic diseases, the most common of which is Down syndrome. In this case, an extra copy of chromosome 21 is inherited from one parent. The condition is also known as Trisomy 21.Continue reading