| A | B |
|---|
| Down Syndrome | having a third copy of chromosome 21 |
| Another name for Down Syndrome | Trisomy 21 |
| Characteristics of Down Syndrome | short, mentally retarted, heart defects, hyperflexibility, low muscle tone |
| Down Syndrome birth ratio | 1 in 800-900 births |
| Edward Syndrome | a third copy of chromosome 18 |
| Another name for Edward Syndrome | Trisomy 18 |
| Characteristics of Edward Syndrome | females, small nose and mouth, receding lower jaw, abnormally shped ears, severe mental retardation |
| Edward Syndrome birth ratio | 1 in 10,000 births |
| Turner Syndrome | the presence of a single X chromosome, genotype is XO |
| Characteristics of Turner Syndrome | females, short, underdeveloped breasts, sterile, webbed neck, normal mental function |
| Jamie Lee Curtis has... | Turner Syndrome |
| Turner Syndrome birth ratio | 1 in 2,000 births |
| Klinefelter Syndrome | born with an extra X chromosome, genotype XXY |
| Characteristics of Klinefelter Syndrome | males, usually tall, long limbs, sterile, usually mentally retarted |
| Klinefelter Syndrome birth ratio | 1 in 500 male births |
