In order to understand about genetic disorders one must start from the beginning. Cells are the basis of the human body. In the cell a nucleus is located. The nucleus is what controls the cell and is where most genetic material is located. Each cell is made up of 46 chromosomes. Chromosomes are composed of DNA. Deoxyribonucleic acid is a chemical that carries genetic information. Located on the DNA strand are genes which are inherited from parents. When genes are passed to offspring diseases are also sometimes past to cause genetic disorders. Genetic Disorders are a mutation in a gene. Mutations are changes in the DNA sequence and can happen anytime, from being a single cell to being 100 years old. There are several type of genetic mutations that occur, chromosome abnormalities, single- gene disorder, multifactorial disorder, and mitochondrial disorder.
Chromosome abnormalities occurs when the chromosome or segment of the chromosome is missing, duplicated, or altered in a way that is not normal to it.
An abnormal number of chromosomes is when nondisjunction occurs in the egg and sperm cell. In nondisjunction copies of a chromosome do not properly separate during division. When this happens two copies of that particular chromosome are placed in the sex cell. When and if this cell is used it will come together with one from another sex cell leaving three copies of this chromosome. Three copies of a chromosome are called trisomy. In most cases trisomy is lethal however there are some instances where it is allowed and when this happens a birth defect occurs. Down syndrome and Turner's syndrome are examples of chromosome abnormalities.
Down syndrome is genetic disorder that causes mental retardation, facial disformations, and decreases muscle tone. The disorder happens on the twenty - first chromosome. It is an example of...