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Genes & Disease
Other important human diseases
Apart from diseases that spread via vectors (see 'Emerging infectious diseases'), diseases can be of the following type:
- Inherited, e.g. muscular dystrophy, williams syndrome.
- Occur via a new mutation, e.g. muscular dystrophy, williams syndrome.
- As a result of environmental stimuli e.g. asbestos causing cancer, bad diet causing heart disease.
- Aging, e.g. alzheimer's, osteoporosis.
Note diseases that can be inherited can be caused by a new mutation. Diseases that are caused by aging may also be a result of environmental stimuli like bad diet. Aging diseases may have a genetic element like a genetic predisposition to getting the aging disease as in alzheimer's disease.
Some examples of other important human diseases include:
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Blood Diseases
Blood cells, consisting of red cells, white cells, and platelets, are made
in the bone marrow. In healthy people, millions of new blood cells are produced each
hour to carry out important body functions. Red blood cells carry oxygen
from the lungs to the rest of the body. White blood cells (leukocytes)
fight infections and illness. Platelets cause the blood to clot, a process
that stops bleeding when there is an injury. The body carefully regulates
the activity of bone marrow to produce the correct number of each type of
cell. If this regulation process is disrupted and the marrow produces too
many or too few cellsor defective cells, a blood disorder occurs.
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Genetic Disorders of Muscle
These progressive muscle disorders are caused by mutations in the DNA, which usually are inherited, or less often caused by new spontaneous mutations.
These defects in the DNA encode the genes for structural proteins or enzymes important for muscle function and are often distinguished clinically by a selective distribution of muscle weakness.
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Neurodegenerative Diseases
So what are neurodegenerative diseases? According to the cecil textbook of medicine, 20th ed, p2050: A varied assortment of central nervous system disorders characterised by gradual and progressive loss of neural tissue.
In layman's terms these diseases are caused by defects in the molecular structure of the proteins of which nervous cells are made of. In the USA alone, more that 2 million people suffer from Alzheimer's. More than 300,000 cases are diagnosed and approximately 100,000 people die per year.
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Keratins and Diseases
In eukaryotic cells, the ability to adopt a variety of shapes and carry out coordinated and directed movements depends on a complex network of protein filaments extending throughout the cytoplasm known as the cytoskeleton (which plays a role in cellular architecture).
The cytoskeleton is composed of three structurally dynamic proteins that reorganise continuously as the cell changes shape, divides and responds to its’ environment. These are microfilaments, microtubules and intermediate filaments.
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