What are chromosomes?

• People are made up of billions of cells that are too tiny to see without a strong microscope.  Inside most of those cells you will find DNA which is made up of chromosomes. Each chromosome holds hundreds or thousands of genes. Genes determine how a person will grow and develop.  They determine eye color, foot size, and all the characteristics that make a person unique. Most people have twenty-three sets of chromosomes.

What are some chromosomal differences?

• Down syndrome is one of the most commonly known chromosomal differences.  People with Down syndrome have an extra twenty-first chromosome. They may exhibit similar physical features such as a flat profile, upward slanting eyes, and low muscle tone. Children with Down syndrome often learn at their own pace.
• Williams syndrome is a chromosomal difference that occurs when genes 26-28 are deleted on chromosome #7. People with Williams syndrome may have medical and learning challenges, but also may exhibit striking verbal abilities, highly social personalities, and an affinity for music.