Genetic disorders are conditions caused by abnormalities in the genetic material contained within our cells.
Some of these genetic abnormalities can lead to cancer, while others lead to various other health conditions. Genetic disorders may be heritable and passed on from family members or non-heritable and acquired during a person’s lifetime. Acquired genetic disorders refer to conditions caused by acquired mutations or changes in parts of the DNA. These conditions only become heritable if the mutation occurs in the germ line. To what extent a person suffers form a genetic condition may be determined to some degree by environmental factors.
Advances in our understanding of the human genome have led to the identification of various genes and gene products as well as improving our understanding of gene expression, its regulation and how these factors interact in genetic disorders.
Improved understanding of the human genome is also gradually demonstrating that almost all diseases have a genetic component. These mutations may not necessarily manifest as disease and may only cause symptoms in the presence of environmental toxins. For example, cigarette smoke can raise the risk of lung cancer in susceptible individuals. Other genetic disorders are congenital and affect a person from the moment they are born. Some disorders are inherited but may only affect a person later in life, such as Huntington’s disease, a neurodegenerative disorder where the typical age-of-onset is 35 to 44 years.
Genetic disorders can also be multifactorial inheritance disorders, meaning they are caused by a combination of several mutations and environmental factors. Conditions as common as heart disease and diabetes are now considered to be multifactorial disorders.
Reviewed by Sally Robertson, BSc