Health conditions caused by many contributing factors are called complex or multifactorial disorders. According to various research work, nearly all conditions and diseases have a genetic component. Although complex disorders often cluster in families, they do not have a definitive pattern of inheritance. Some hereditary disorders, such as sickle cell disease and cystic fibrosis, are caused by variants (also known as mutations) in single genes. MedlinePlus. (2021). In my area of practice and on a personal basis I have come across patients and community members who suffer from Sickle Cell Disease.
Sickle cell disease is caused by a mutation in the hemoglobin-Beta gene found on chromosome 11 making it the most inherited blood disorder in the United States. Approximately 100,000 Americans are affected by the condition. In people with sickle cell disease, abnormal hemoglobin molecules – hemoglobin S – stick to one another and form long, rod-like structures. These structures cause red blood cells to stiffen and assume a sickle shape. Their shape causes these red blood cells to pile up, causing blockages and damaging vital organs and tissue. The disease is primarily seen in people of African descent (Genome.gov,2020).
In sickle cell disease, a baby born with disease inherits a gene for the disorder from both parents. When both parents have the genetic defect, there’s a 25 percent chance that each child will be born with sickle cell disease. If a child inherits only one copy of the defective gene (from either parent), there is a 50 percent chance that the child will carry the sickle cell trait. People who only carry the sickle cell trait typically don’t get the disease, but can pass the defective gene on to their children (Genome.gov,2020).
For a very long time, the life expectancy for people with sickle cell disease was very short. They were not expected to survive childhood. However, with advancement in science and medicine, preventive drug treatment, improved medical care and aggressive research, half of sickle cell patients live beyond 50 years. Treatments for sickle cell include antibiotics, pain management and blood transfusions. A new drug treatment, hydroxyurea, which is an anti-tumor drug, appears to stimulate the production of fetal hemoglobin, a type of hemoglobin usually found only in newborns. Fetal hemoglobin helps prevent the “sickling” of red blood cells. Patients treated with hydroxyurea also have fewer attacks of acute chest syndrome and need fewer blood transfusions (Genome.gov,2020).
Researchers are experimenting with attempts to cure sickle cell disease by correcting the defective gene and inserting it into the bone marrow of those with sickle cell to stimulate production of normal hemoglobin. Recent experiments show promise.
However, in African countries where accessing quality healthcare is a huge challenge, and it’s estimated that that approximately 40 million people in Nigeria (which is the epicenter of SCD in Africa), are healthy carriers of the disease, the preventive strategy is through campaigns for people to know their genotype status before dating and getting married. It has become a requirement for getting married (DW, 2022). My friend and her husband who got married in 2013 were asked to provide their genotype status before they were allowed to wed.
MedlinePlus. (2021). What are complex or multifactorial disorders? – MedlinePlus
medlineplus.gov/genetics/understanding/mutationsanddisorders/complexdisorders/
About Sickle Cell Disease – Genome.gov
https://www.genome.gov/Genetic-Disorders/Sickle-Cell-Disease
May 26, 2020 ·
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