What is sickle-cell anaemia
Sickle-cell anaemia is a hereditary, homozygous, genetic blood disorder that occurs within a person who has abnormal haemoglobin on their red blood cells. The Haemoglobin are sensitive to low amounts of oxygen in the body which makes them transform into sickle or crescent shapes. This causes the abnormal haemoglobin to become stiff and sticky blocking blood flow to important organs and tissues. Healthy red blood cells will survive within the body for 120 days however, sickle-cells will rupture and break down within 20 days. The spleen is an organ which recycles old red blood cells and fights infection. Sickle-cells cause the spleen to become overwork and blocked, the bone marrow often can not keep up with the frequent lack of red blood cells and this can cause anaemia.
Symptoms of sickle-cell anaemia are usually presented in early childhood. Patients usually show symptoms between six to eight months of age. The symptoms may include pain, fever, swelling of the hands and feet but vary from person to person. Some people may show mild symptoms where others may require frequent hospital visits. This disease affects many people throughout the world mainly those whose ancestors migrated from Africa. A person who is born with the homozygous genotype “SS” will have sickle-cell anaemia.
This image shows carrier parents with genotype Ss. The parents will produces a future generation with a twenty-five percent chance of having sickle-cell anaemia genotype SS, twenty-five percent chance of not having sickle-cell anaemia genotype ss and a fifty percent chance of producing a carrier genotype Ss.
DNA and protein synthesis
DNA is made up of nucleotides, these are broken down into sugar molecules, phosphate molecules and a base. There are four base a nucleotide could have, Thymine, Adenine, Cytosine and Guanine. DNA produces large chains of amino acid in a consistent order depending on the nucleotides gene coding. DNA continuously replicates itself, it unzips part of the ladder and new DNA strands will connect up to form additional DNA strands ensuring the survival of DNA for many years. Nucleotides are linked together to make the DNA ladder strand also known as a double helix. Amino acid contains around 20 molecules that are combined to form protein in living organisms.
Darwin’s theory of evolution be natural selection
Darwin’s theory of evolution by natural selection describes variants in plants, animals and fossils. Darwin’s idea challenges the idea God made all that live on earth. His scientific research was published twenty-eight years after he started. Darwin stated, “individuals with characteristics most suited to the environment are more likely to survive and breed successfully, this will allow them to pass on their survival characteristics to the future generations.”
Malaria is a disease carried by mosquitos, when they feed on human blood they pass on a parasite. The single-celled mosquito parasite multiplies in the mosquito’s intestines as well as red blood cells in humans. Areas such as Africa, South Asia and Middle East are at risk of catching the malaria disease. Throughout the generations and following Darwin’s theory of natural selection humans within these areas have evolved in order to survive. Sickle cells anaemia appears more within these countries as a survival trait within the human body. The sickle shape cells die off quicker than the regular red blood cells which causes the parasite carrying the malaria disease to become stuck within them and die along with the sickle shaped red blood cells.
Current piece of research on sickle-cell anaemia
A recent piece of research on sickle-cell anaemia published by Ballas, Samir in June 2002 explains how sickle-cell anaemia influences a person’s life and what steps are taken to relieve pain. Ballas states “…social interactions, intimate relationships, family relations, peer interactions, education, employment, spirituality and religiosity” are all affected when a person is sickle-cell anaemic. There are many different therapies used to manage the disease, a sympathetic approach including pain management, blood transfusion and treatment of organ failure.
Individuals undergoing pain management will be assessed as to what therapy and utilisation period is needed, also an assessment into what medication would benefit the patient will be assessed for adequate pain relief.
Intense chest syndrome is one of the common organ failures amongst the sickle-cell anaemic patients. This syndrome is managed through hostile treatments including but not limited to multiple antibacterials and blood transfusions depending on how severely the patient’s symptoms are. Throughout the last decade there has been significant advances in the way sickle-cell anaemia patients are cared for, one most important aspect was the discovery of hydroxyurea and how this can help patients with sickle-cell anaemia.
In conclusion as humans have two chromosome 11s a person can only have sickle- cell anaemia if both chromosome 11s are affected. If only one chromosome 11 is affected that person will be a carrier of the sickle-cell anaemia disease. Although the disease is more common in areas with malaria as the mutation in the DNA helps fight malaria it can still be found throughout the world.