What is a genetic disorder ?
A genetic disorder is a medical condition or health problem that is caused by an anomaly or error in one’s genome or genetic material. It is estimated that about 65% of the world’s population has some form of a genetic mutation that they are born with, which is known as a congenital genetic mutation. This results in a health problem that is associated with a genetic disorder which may manifest sometime during the life time of an individual. By using this estimate, it means that in Canada, more than 24 million individuals of the population may potentially have a health problem that is associated with a genetic mutation or a combination of genetic mutations that they were born with. In the province of Alberta, Canada, this estimate is calculated to be more than 2.9 million individuals who may potentially have or will develop sometime during their lifetime; a health problem that is associated with a genetic mutation or a combination of genetic mutations that they were born with.
To date, there is an estimate of more than 6,000 known genetic disorders being classified or identified, with an increasing number added each year as more biomedical research discoveries advance in the field of genome medicine and medical genetics. Most of these distinct genetic disorders or health problems are considered rare in themselves; usually affecting less than 1 in 2,000 individuals in the world’s population. However, due to the fact that several thousand genetic disorders are known to exist, it is approximated that 1 in 21 individuals of the world’s population is affected by a “rare genetic disorder”. This means in Canada, more than 1.8 million individuals may potentially have a rare genetic disorder. Moreover, in the province of Alberta, Canada, more than 200,000 individuals may possibly have a rare genetic disorder. In fact in Canada, it is estimated that more than 500,000 children currently have some form of rare genetic disorder, of which many of them still do not yet have any defined genes or genetic mutations that can be used to diagnose specifically the type of rare genetic disorder and the cause of such rare genetic disorder. Frequent DNA testing / genetic testing of individuals of the population will help to diagnose genetic disorders as well as unravel the cause of the genetic disorders among these individuals. Such genetic diagnosis will inevitably help to improve the clinical management and betterment of health of such individuals.
A genetic disorder is classified as a hereditary disorder when it is inherited from one or both parents. Genetic mutations can occur in a manner known as de novo or spontaneously in the germline of gametes: the egg or sperm of the parents, or before the human embryo develops. For instance, it is estimated that single nucleotide de novo genetic variants occur at a frequency of 1.0 to 1.8 × 10–8 per nucleotide per generation in the germline of individuals. Genetic mutations can further be inherited from one or both parents in which such mutations are prevalent in the gametes (sperm and egg) and all cells of the bodies of such individuals. Most of these genetic disorders arise before the birth of an individual and may present with health problems in some individuals starting as early as infancy (an example is Phenylketonuria), while the health conditions of other individuals may manifest at later stages of their lives (an example is late-onset Alzheimer’s disease).
A genetic disorder may be caused by mutations in a single gene (known as monogenic disorders), or collectively by mutations in multiple genes (known as polygenic disorders). Genetic disorders can be further caused by a chromosome abnormality, also known as a chromosomal disorder; that is, there are problems with the structural integrity of a chromosome or more than one chromosome in an individual (an example is Down syndrome or Trisomy 21). To date, it is estimated that 1 in 50 individuals is affected by genetic disorders caused by single gene defects, while 1 in 263 individuals is affected by genetic disorders caused by a chromosome abnormality. This means in Canada, more than 760,000 individuals may potentially be affected by a single gene genetic disorder, while in the province of Alberta, Canada, this estimate is more than 84,000 individuals. In regards to individuals with chromosome abnormalities or chromosomal disorders, in Canada, it is estimated to possibly have more than 144,000 individuals currently with a chromosomal disorder, while in the province of Alberta, Canada, this estimate is more than 16,000 individuals.
Apart from hereditary genetic disorders, many other health problems are caused by an acquired disease in which genetic mutations in a small number of cells in the body of an individual have occurred leading to the onset of an acquired disease. Cancer is an excellent example of an acquired genetic disease. Both hereditary and acquired genetic disorders can also be a consequence of multifactorial causes. In this manner, genetic, environmental and other factors contribute collectively towards the cause of the health problems of individuals at some stage in their lifetime.
At CEN4GEN, we offer numerous DNA testing / genetic testing options that can be used to diagnose monogenic and polygenic genetic disorders, as well as chromosomal disorders. To learn more about how our testing options can suit your needs, contact us at [email protected], and a representative will guide you through the testing process and provide more information for you and your healthcare provider. CEN4GEN is a DNA testing company / DNA testing organization / Genetic testing company / Genetic testing organization offering affordable DNA testing services / Genetic testing services in Edmonton, Alberta, Canada.