A disease is an abnormal condition
that effects an organism or part of an organism. In humans, diseases are often
used to refer to the conditions that cause pain, distress or death. diseases
can be divided into four main categories, which are: deficiency diseases,
infectious diseases, physiological diseases and genetic diseases.
regarding genetic diseases, it is
mainly caused due to an abnormality in a specific gene or the entire genome.
for example, Sickle cell which is a genetic haematological disorder characterized by abnormal red blood cells that
assume sickle shape (Peterson, 2009). sickle cell, is one of the most prevalent
diseases in the world as more than 300 thousand effected infants are born each year
with sickle cell (Opoka et al., 2017). sickle cell disease is found in
higher rates in sub-Saharan Africa, the middle east, the Mediterranean basin
and India because of the protection that the sickle cell provides against
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understand it!! (Piel, Steinberg and Rees, 2017). therefore, in these regions people with sickle cell disease are the fittest
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cell disease can affect the formation of red blood cells from the normal round
RBC to a sickle shape RBC. The deformation of RBS will result in shorter RBC
life span and lower body oxygen level due to less number of oxygen molecules been
carried with the sickled shaped RBC (William and Shiel., 2016). These signs and
symptoms usually appear in early age. blood disorder and transfusion journal mentions
that sickle shaped cells live only 10-20 days unlike the normal RBCs that have
90- 120 days life expectancy (Omicsonline.org, n.d.)
. The shorter life span of
the RBC can result in Anaemia, which is the decrease
in the total quantity of red blood cells. The deformed cells can block the
blood flow by clumping together and sticking to the walls of blood vessels
causing one of the major symptoms of sickle cell disease which is the pain crisis.
Another symptom of sickle cell disease is the swelling of hands and (Ashley-Koch, Yang and Olney, 2000). The severity of these symptoms varies from a person
to another tremendously. some people have mild symptoms while others are
hospitalised because of more serious complications.
Red blood cells contain
a molecule called haemoglobin, which carries oxygen throughout the body. sickle
cell disease results from the alteration and mutations in the haemoglobin. This
alteration makes the cell no longer capable of carrying large amounts of oxygen
as the normal blood cells. Haemoglobin usually has two alpha chains and two
beta chains. The main cause of the sickle cell disease is the homozygosity of the
sickle cell beta globin gene (Hb S) at the location of the beta globin gene (Saiki et al., 1985). The difference of the (Hb S) allele and the normal allele
(Hb A) is the adenine base. As the S allele has a thymine nitrogen base instead
of an adenine nitrogen base at the second position of the sixth codon of the
beta chain gene. this results on a substitution of a glutamic acid by a valine
in the expressed protein.
There are several types of sickle cell disease which
are Haemoglobin SS disease the
most common and the most sever type of the sickle cell diseases that occurs
when a person inherits copies of the HbS from both of his parents forming haemoglobin known as HbSS,
Haemoglobin SC disease the second most common type of sickle cell disease and
it occurs when a person inherits a HbS gene from one of his parents and the Hb
C gene from the other , (Haemoglobin SD , haemoglobin SE, and haemoglobin SO)
are other types of sickle cell disease that are very rare and Sickle cell trait (Centers for Disease Control and Prevention, 2016).
People with sickle cell trait inherited only one mutated gene (HbS).
blood test (haemoglobin electrophoresis) can tell whether a person have a
sickle cell disorder or is a healthy carrier. Then doctors can describe some
medications that will relief patient with sickle cell.
There are many ways used
as a cure for sickle cell disease. One of the ways to treat sickle cell disease
is bone marrow transplant and the best candidates for such treatment are
children younger than 16 years who have a matching donor and are suffering from
severe implications (Bolaños-Meade and Brodsky, 2009). The treatment has 3 phases.
In the first phase doctors prepare the patient for the bone marrow (stem cell)
transplant by giving the patient a strong type of medications that weakens or
destroys his own bone marrow, stem cells and infection fighting system so that
the patients body does not reject the donors blood cells called chemotherapy.
The second phase is when the actual transplantation starts by giving the
patient the collected stem cells by infusing them through a catheter (Weill
Cornell Bone Marrow Transplant Program, n.d.). The third phase is when doctors provide
an excellent consistent care for the patients to make sure that the treatment
is successfull. However, there are some possible complications that can arise after the
transplantation due to the chemotherapy or the response of the immune system to
the new stem cells.