Updated by: Arabinda Naik
| Down's Syndrome | Turner's Syndrome |
| In this, there is the presence of an additional copy of chromosome number 21. | In this, there is the absence of one chromosome, i.e., 45 with X0. |
| This involves autosomes. | This involves sex chromosomes. |
| The affected individual has short stature, partially opened mouth, tongue protrudes mental retardation, defective development of CNS and broad palm. | The affected individual has short stature, webbed neck and underdeveloped breast, rudimentary gonads, lack of menstrual cycle during puberty ,lack of secondary sexual characters. |
| The affected individual is fertile. | The female are sterile. |