Genetic Diseases – Term Paper

Genetic Diseases that Affect the Respiratory System

          Living organisms need a set of instructions to control their growth and development, reproduction, and general functioning. These guidelines need to be packaged in an appropriate molecule called DNA. When this molecule changes or mutates, a genetic disorder may occur because of a communication breakdown. Also, when entire chromosomes are added or subtracted, abnormalities may arise. Exposure to radiations from the environment or cigarette smoke may also cause multifactorial disorders. These disorders, regardless of the causative case, can then be passed onto ones lineage through the germ cells.

          One of the genetic diseases that affect the respiratory system is emphysema. Genetic emphysema is caused by a shortage of alpha-1 antitrypsin gene. It is also called alpha-1 protease inhibitor deficiency or hereditary pulmonary emphysema. One is likely to inherit this gene from the parent hence increasing their chances of suffering from the disorder.

          Genetic emphysema affects the protein-coding DNA genes since the alpha-1 antitrypsin is protein in nature. For the case of smokers, all chromosomes (metacentric, submetacentric, telocentric, acrocentric) are affected by mutations that aim to repair the damages caused by smoking. Therefore, those that indulge in cigarette smoking increase the chances of having genetic emphysema. When an autosomal codominant pattern exists, one gene may exist in two different versions, and each will fight to be expressed. For that reason, both versions majorly contribute to the trait which they influence. For instance, M, an SERPINA 1 gene manufactures the required level of aplpah-1 antitrypsin. SERPINA 1 issues instruction for the production of the serine protease inhibitor which is responsible for the inhibition of particular enzyme activities such as those facilitated by the enzyme elastase which acts on disease-causing bacteria. The M allele exists in a pair within a cell. Any deviation from the normal, coupled with alleviating factors such as smoking causes a reduction in the alpha-1 trypsin levels hence resulting in emphysema. Case in point is a person with the S and Z allele. The S allele is meant to produce alpha-1 antitrypsin with moderation. The Z allele, on the other hand, produces the protein in small amounts. These alleles can pair in the following ways: SS, SZ, ZS, and ZZ. Assuming that the autosomal codominant pattern applies; for the SS combination, the antitrypsin levels will be acceptable hence preventing the possibility of emphysema. The SZ and ZS combinations are likely to result in the small production of antitrypsin hence the high likelihood of the occurrence of emphysema. Lastly, the ZZ pairing predisposes one to the greatest risk of emphysema because with it comes the production of the lowest levels of alpha-1 trypsin. 

          Genetic pulmonary emphysema leads to the partial formation of chronic pulmonary obstructive disease which is characterized by the abnormal enlargement of air sacs that are located in the lungs. Alpha-1 antitrypsin is a protein, in nature. It is produced in the liver cells, and when it circulates in the blood, it is likely to affect both the lungs and the liver (Rogers 177). The white blood cells contain the enzyme neutrophil elastase which is responsible for the destruction of any invading bacteria. Aplha-1 antitrypsin, when released into the lungs, counters elastase to facilitate its inactivity. If left uncontrolled, elastase can destroy the lung tissue by acting on it thus the importance for the alpha-1 antitrypsin since it is impossible for inactivated elastase to destroy this tissue. A shortage of the protein means that elastase will continue acting on the lung tissue hence resulting in genetic emphysema.

In the lungs, the protein is responsible for breaking down the walls of the alveoli. Consequently, these are enlarged, stretched, and over-inflated and start to malfunction. In other circumstances, the attack by this excessive amount of white blood cells causes the alveoli to become narrow so that air experiences some barrier when it finds its way in the sacs. Some of these sacs eventually are destroyed by this alpha-1 antitrypsin. They eventually stop functioning. The result is that the surface area for gas exchange becomes smaller hence reducing the rate of oxygen and carbon dioxide exchange. Once these air, sacs have been damaged, they are irreparable, and the victim suffers labored breathing and persistent coughing. Other symptoms include wheezing and an inability to perform any exercises. Treatment plans include medication and therapy. Inhaled bronchodilators such as anticholinergics aid in the relaxation and unclogging the air passages that lead to the lungs (Rogers 189). Drug treatments are also effective in improving ones ability to exercise. Supportive therapy includes oxygen administration where electricity drives oxygen to the lungs. This treatment is informed by the fact that independent breathing is affected by emphysemas progression over time. Other evidence-based treatment options include pulmonary rehabilitation and surgical procedures especially in the case of severe emphysema. Additionally, individuals are encouraged to cease smoking to promote the proper functioning of the lungs.

Statistically, those between the ages 20 and 50 are more likely to display signs of lung disease if they inherit these genes from their folks. In America, 2011 saw that about 4.67 million people who registered the disorder were aged above 45 years with the number of women suffering from the conditions on a steady increase compared to their male counterparts. An estimated 3.75 million non-Hispanic whites suffered emphysema in the same year. The Word Health Organization statistics as at 2004, indicated that a whopping 64 million people the world over reported to have suffered from Chronic Obstructive Pulmonary Diseases wherein lay emphysema. The disease affects both adults and infants with 10% of the children subsequently developing liver disease. 15% of adults, on the other hand, may suffer liver cirrhosis as a result of emphysema. Additionally, in 2004, emphysema was most prevalent in Alabama and Kentucky while Minnesota and Washington registered the lowest cases of emphysema. In Australia, smokers are six times likely to have emphysema compared to non-smokers with the risk extending to those that may have quit smoking.

Genetic Diseases that Affect the Cardiovascular System

          An array of genetic disorders affects the circulatory system. These include high blood cholesterol, congenital heart disease, and arrhythmia. Of interest is arrhythmia which is defined as a defect in the rhythm of the heartbeat. When it beats too fast, then the condition is called tachycardia while an unusually slow heartbeat is called bradycardia. The lack of either speed is called fibrillation. The heart is unable to pump adequate blood that is needed for an efficient circulation, and the results are damaging.

          The heart is powered by an electrical system which is in charge of the rhythmic pumping of blood arising out of heartbeats. One pulse translates to the transmission of an electrical signal from the atrium to the ventricles. Thanks to this transmission, the heat pumps blood. The sinoatrial node is a mass of cells from which the electrical signal begins. In one minute, 60 to 100 heartbeats are fired off by an electrical signal from the sinus node. Such is the ideal case for a healthy adult. These electrical signals then traverse different pathways in the right and left atria causing their contraction and eventual pumping of blood into the ventricles. Next, the atrioventricular nodes slow down the electrical signals allowing the ventricles adequate time to be filled with blood. From the atrioventricular node, the electrical signals then progress to the bundle of His pathway which is split into right and left bundles. These channels carry the electrical signal which prompts the ventricles to contract. Resultantly, blood is pumped to the lungs and all other parts of the body. Finally, the relaxation of the ventricles causes the synchronous process to start in the sinoatrial node, and it proceeds in the same fashion. Any disorganization in the process results in arrhythmia.

          Most genetic arrhythmias are products of spontaneous gene mutations. Hypertrophic obstructive and non-obstructive cardiomyopathy dilated cardiomyopathy, and dysplasia are examples of genetic structural changes. Arrhythmias are recognizable by the genetic substrate which forms the cardiac electrophysiologys molecular basis. These genetic substrates also enable the understanding of the various ion channels which contribute to the possible occurrence of arrhythmia. Consider the cardiac ion channels whose cardiac action potentials are determined by the ion activities. Ions are supposed to move in a proper way so that the cardiac potential of each chamber of the heart is well-coordinated. In particular, LQTS (Long QT Syndrome) which results from the hearts electrical activity is heritable. Some of the susceptibility genes perform the encoding of critical ion channels which form a-subunits while others encode b-subunits. The susceptibility genes also encode adapter proteins which include ankyrin-B and AKAP9. When these genes mutate, they cause defects in the scaffolding and adaptor proteins. Consequently, the ion channels are affected and the electrical signals normal functioning is deterred (Stockley 50). Genetic arrhythmia is characterized by a non-linear relationship between the genotype and the clinical phenotype. In effect, any mutation in the Na+ channel gene SCN5A leads to completely different arrhythmia syndromes. These include LQTS3 and BrS1 both in locus 3p21. The chromosome 1q42-q43 is the most commonly affected by the arrhythmic disorder where this autosomal-dominant syndrome is likely to be manifested.

          Arrhythmic manifestations include heart races, profuse sweating, and chest pain. Weak heart beats may prompt a doctor to prescribe pacemakers. These devices are implanted close to the collarbone with electrode-tipped wires running into the heart through the blood vessels. When the heart beat slows down below normalcy, the pacemaker sends electrical signals through these electrode-tipped wires. These signals lead the heart to increase its rhythm to normal levels. Tachycardia treatments include medications, catheter ablation, and vagal maneuvers. Appropriate medication is prescribed to retain and sustain normalcy in the heart beat. It is necessary that these be taken religiously as prescribed to avoid further complications. Catheter ablation involves the threading or a catheter to the victims heart via the blood vessels. The tips if these catheters are fitted with electrodes which ablate a microscopic spot of the hearts tissue. Consequently, an electrical block is erected along the path that was responsible for the arrhythmia (Stockley 76). Vagal maneuvers, on the other hand, do not need additional gadgets or interventions. They are simple exercises that can be performed whenever one experiences heart races. These include coughing, holding ones breath, or dunking ones face in ice-cold water. Such measures are instrumental in cases where an arrhythmia is of a supraventricular nature.

          Statistical data indicates that at least 33.5 million people all over the world suffer atrial fibrillation. According to the 2013 study, Americans amount to 2.7 million of this population. From 2012 to 2013, 47% of hospital consultations in England were arrhythmia-related. It is also indicated that women are at a higher risk of arrhythmia compared to their male counterparts. It is fueled by the differences in electrophysiological properties between men and females. Although children are affected, most cases of arrhythmia are recorded in adults aged 60 years and above. Arrhythmias in children are often caused by certain medications, infections, or chemical imbalances in their body systems. If left untreated, the arrhythmia may lead to sudden cardiac death.

Conclusion

The weighty matters in this paper all mirror the fact that all body systems are meant to work without defects to achieve homeostasis. The cause of most diseases is the lack of equilibrium. When one system fails to perform its functions, then a number of other systems are affected, and diseases and complications arise. The respiratory system ensures that the oxygen-carbon dioxide levels are kept at an absolute constant to avoid toxicity that may lead to diseases such as pneumonia and asthma. In the same breath, the circulatory system works to maintain a continuous supply of blood to all parts of the body. It is apparent that shortage of oxygen for some time; leads to the death of brain cells and a resultant brain damage. If the respiratory system fails to deliver a constant oxygen supply, the circulatory system will be affected by toxic wastes and an altered oxygen-carbon dioxide exchange. The same applies when the cardiovascular system malfunctions; point in case is the coronary artery disease where water and salts are retained in the heart depriving oxygen of a medium of transportation. The growth of cancer cells in some of these body systems has far-reaching effects. The respiratory system is prone to lung cancer. The growth of these cells in the lungs curtails the regular breathing process and if left untreated may result in death. The cardiovascular system, on the other hand, suffers blood cancer in the form of leukemia. Genetic factors come into play when one considers those conditions that can be inherited from parents. Gene mutations may also result in a position such as genetic pulmonary emphysema for the respiratory system and arrhythmias for the cardiovascular system. Statistics indicate that these genetic diseases are not uncommon to the masses with women being at the highest risk of suffering the consequences. Men and children also suffer from genetic diseases and illnesses. Evidence-based care aids in the treatment of these diseases and individuals are encouraged to go for regular screening since early detections and interventions often result in a successful treatment plan.

Works Cited

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Rogers, Kara. The Respiratory System. New York, NY: Britannica Educational Pub., in association with Rosen Educational Services, 2011. Print.

Stockley, Robert A. Molecular Biology of the Lung: Volume I: Emphysema and Infection. Basel: Birkhauser Basel, 1999. Print.

Whittemore, Susan, and Denton A. Cooley. 

The Circulatory System. Philadelphia [Pa.: Chelsea House, 2004. Print.