A change in a gene's DNA is called a mutation.
A mutation can result in the affected gene to no longer carry instructions to build a protein.
If sperm and eggs carry a mutation, then the offspring will inherit the mutated gene and will have the disorder, too.
Genetic disorders are the result of inheriting gene mutations.
Examples of inherited recessive genetic disorders are cystic fibrosis and sickle cell disease.
If the mutated allele is dominant, or a person inherits 2 of the mutated recessive allele, then the person will be affected by the allele's disorder.
Pedigree analysis is used to see the risk of a person inheriting the affected gene.
Cystic Fibrosis affects the movement of fluid in and out of cells.
This causes a thick, sticky mucus to form in the lungs and digestive tract.
- Breathing difficulities due to mucus blocking the airways of the lungs.
- Lung infections due to beacteria becoming trapped in the mucus.
- Malnutrition due to problems digesting food.
- Bone disease.
Treatments involve physiotherapy and massages, various medications and a good diet.
Sickle Cell Disease
Sickle cell disease is caused by a mutation that changes haemoglobin molecules. This causes them to absorb less oxygen. Due to this, red blood cells take a sickle like appearance.
- Feeling weak and tired due to there not being enough oxygen in your body.
- Sickle cell crisis, which is a sudden pain caused by the altered red blood cells that have formed clumps in the bloodstream. This results in blocking of the blood flow to organs and causing organ damage.
Treatments include various medications, lots of fluids and blood transfusions.