Genetic disorders are diseases caused when certain mutations occur in DNA. There are a wide range of genetic disorders that are each caused by different genes and each have very different symptoms. There are three kinds of genetic disorders: single-gene disorders, chromosome abnormalities, and multifactorial disorders. In this document we will cover the three types of genetic disorders, examples of each type, and possible treatment of particular disorders such as Huntington’s disease, Down syndrome, and Alzheimer’s disease.
Life on Earth relies on the mutation of DNA. Mutations allow organisms to evolve, making them healthier and more capable of surviving. While many mutations occur that help species to survive, there are also just as many mutations that do not help species survive. In some cases, organisms die because the mutation of their DNA makes it impossible for them to survive. For some species, mutations occur that do not help them to survive, but they still live. This could be the beginning of an inherited genetic disorder.
Genetic disorders are abnormalities of the human body, caused by mutations in DNA. These mutations are random unless caused by the environment. There are three categories of genetic disorders: single-gene disorders, chromosome abnormalities, and multifactorial disorders.
As said by Richard Twyman, “Single-gene disorders are caused by defects in one particular gene, and often have simple and predictable inheritance patterns (http://genome.wellcome.ac.uk/, 2003).” Single-gene disorders usually cause symptoms by altering or changing the amount of a protein made by the mutated gene. Offspring of a parent with the mutated gene have a fifty percent chance of inheriting the mutated gene.
Huntington’s disease is a single-gene disorder that causes the brain to lose their memory, speech, and fine motor skills. Huntington’s disease occurs later on in life, symptoms usually occurring between the ages of 40 and 50. In the United States, about 1 in every 30,000 people has Huntington’s disease (“Huntington’s Disease” Genetic Science Learning Center, 2006).
The gene for Huntington’s disease is found only on the X chromosome, making it a sex-linked trait. Since the gene is found on the X chromosome, it can only be given to offspring by the mother’s DNA. Sex-linked traits can only be expressed if there is not another X chromosome to counter the mutated gene with its normal gene. This puts males (have X and Y chromosomes) at a huge disadvantage because they do not have another X chromosome like females (have two X chromosomes) do. Males with mothers who are carriers of the mutated gene have a fifty percent chance of inheriting disease because there are two X chromosomes (one has the mutated gene) in which they can be given. This is why sex-linked traits, such as the gene for Huntington’s disease, most often affect males. Although females of mothers with the mutated gene are less likely to be affected by the mutated gene, they...