What is a genetic disorder?
A genetic disorder is a disease caused partly or wholly when there is a change from the normal DNA (deoxyribonucleic acid) sequence.
DNA is the molecule that contains our genetic code, and is found in all our cells. DNA contains biological instructions that make each living organism unique. Chromosomes are made up of DNA, and segments of DNA in specific sequences are called genes.
Causes of genetic disorders:
Several factors can cause genetic disorders, for example:
- damage to chromosomes
- a mutation in one gene (monogenic disorder)
- mutations in multiple genes (multifactorial inheritance disorder)
- a combination of gene mutations and environmental factors
Nearly all diseases have a genetic component involved, with some of them caused by mutations that are passed down from the parents, i.e., inherited, at birth. Sickle cell disease is an example of an inherited disease, which affects the haemoglobin in red blood cells.
Other diseases which include many cancers and certain types of neurofibromatosis which causes tumours to form on nerve tissue, are caused by acquired mutations in a gene or genes during a person’s lifetime. There are not inherited but can occur due to environmental exposure, e.g., cigarette smoke.
Today’s article will discuss hereditary conditions brought about by genetic disorders.
The cause of any cancer is still a scientific mystery. However, what researchers have discovered is mutations in certain genes, i.e., BRCA1 and BRCA2, cause some cancers.
Men with BRCA1 have a higher risk of getting prostate cancer, and BRCA2 has been found to cause cancers in the male breast, pancreas, prostate and elsewhere. Women who inherit the mutated gene have higher risk of getting cancer and in both breasts. If a family member has any form of cancer, it is important for you to seek medical advice on regular screening.
Colour vision deficiency:
Also known as colour blindness, it is the decreased inability or total inability to distinguish the various colours, making simple daily tasks like choosing clothing, reading traffic lights or selecting fruit very challenging and dangerous as well.
When compared, men are more likely to have colour blindness than women, as the genes responsible are on the X chromosome. Men have 1 X chromosome and since women have 2 of them, one X chromosome can compensate for the second defective chromosome.
A scientific theory suggests that the same genes which enabled our ancestors survive famines, now work against us, as food is plentiful. Science has discovered obesity disorders, an example being Prade-Willi syndrome, are related to defective genes.
Family history of heart disease, diabetes, stroke, high blood pressure:
Here again, genes play a big part as children of parents having heart disease, diabetes, stroke and high blood pressure, are at higher risk of getting the same disease. Both parents or one parent suffering from a congenital heart defect have a high risk of passing it on to their children.
Acne has been seen in children where one or both parents suffer from it. The affected parent may have a gene that overproduces sebum (oil) leading to oily skin and acne or pimples.
Families with a history of having either identical or fraternal twins, see a repetitive pattern happening down the line. This is caused by a gene that causes hyperovulation, i.e., the woman releases multiple eggs during ovulation.
A sensitive and hair-raising (no pun intended) topic found mostly in men, but women can suffer from it too. Scientists have found baldness linked to abnormalities in several genes from either one or both parents. Defective “hairless” genes cause a rare and permanent type of baldness called alopecia universalis through which all body hair can be lost.
There are many other hereditary genetic disorders some of which are serious and life-threatening, but the ones listed above are the most common. We hope this general summary has given some insight into hereditary genetic disorders, but the information should not be taken as medical advice. Please consult a qualified medical practitioner for proper medical information and treatment on this subject.
9th July 19:50 2020