Pathophysiology

Pathophysiology Study Guide

happens at the time of conception when one of the gametes, egg or sperm, acquires two copies of chromosome 21. The second type of down syndrome is translocation, in which one of the chromosomes breaks and the broken fragment attaches itself to another chromosome. The third, and most uncommon type of down syndrome, is mosaicism in which some of the cells have normal chromosome pairs while other cells possess chromosome 21. Individuals affected by down syndrome are likely to have a high probability of immune malfunctioning, heart attacks, and leukemia. Mutations Another form of genetic disorder is gene mutation. Mutations refer to the permanent change in the sequence of DNA. These mutations can either be hereditary or acquired. The former is the mutation that is acquired by the parents, and is present in all the cells of the body, which is also known as germ- line mutation. This mutation is present in either or both the egg or the sperm cells; the resultant fertilized egg will have this gene mutation. Acquired mutations, also known as somatic mutations, are genetic disorders that are acquired by the person at some time during their life, and are not present in all the cells of the body. These disorders are caused by environmental factors, like harmful ultraviolet radiations, chemicals, or viruses that cause the DNA to self-replicate. These gene mutations are not transferred to the next generation. One example of gene mutation is sickle cell anemia, which is the result of point mutation in which the blood cells are affected and take the form of a sickle shape. These cells produce clogs in the capillaries and affect normal blood circulation in the body. Another example of mutation is the occurrence of thalassemia, in which the ability of the blood to produce hemoglobin is reduced, which results in blood-related diseases like anemia. Thalassemia can be transferred to the next generation. There are two types of thalassemia: beta thalassemia and alpha thalassemia. In the beta type, the beta globin genes are affected, while in the case of alpha thalassemia, alpha globin genes are mutated. Another instance of mutation is cystic fibrosis, which causes thick, sticky mucus in the lungs and digestive system. It is caused by the mutation in a single gene that influences the cystic fibrosis trans-membrane conductance regulator (CFTR) protein in the body. Huntington’s disease is another instance of single gene mutation, which causes the neuronal cells to die in some parts of the brain, which causes severe muscle spasms. 1.4 Neoplasia Neoplasia is a condition in which abnormal and uncontrollable growth of cells and tissues occurs in the body. Neoplasm can either be hereditary or acquired. These tumors are formedwhen a genetically damaged single precursor cell is proliferated in a monoclonal manner. Tumors are formed mostly among the liable cells, and then in stable cells, while the permanent cells are least affected. There are two kinds of neoplasm cells: benign neoplasms and malignant neoplasms. Nomenclature/Classification/Naming of Neoplasias Characteristics of Benign Neoplasms Benign tumors are the formation of a single mass, formed by matured tissues, which are spread

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