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Genetic Diseases Final

A genetic disease is that sickness you can never avoid. The question is, how many genetic diseases are there? What are some of the rarest genetic diseases and why are they rare? What is the most common genetic disease and why?

There is over 6,000 genetic diseases that we are aware of, and given how many genes there are and how many variations there can be that is a very low number. Humans have 24,000 genes, imagine if every one of those genes had an abnormality, and every genes could have three variations, that is 72,000 genetic diseases, twelves times more than what we are aware of.

Hutchinson-Gilford Progeria is one of the most rare genetic diseases, and perhaps the scariest. This is disease is extremely well known despite there only being 130 reported cases since 1886. The disease affects 1 infant in 4,000,000. At birth the child appears like a normal healthy baby, however after the toddler years the signs of the disease begin to show. Hutchinson-Gilford Progeria is characterized by the appearance of significant aging, growth is slow and skin looks old. The disease causes joint abnormalities, hardening of the arteries, and loss of subcutaneous fat. The life expectancy for a child diagnosed with Hutchinson-Gilford Progeria is about 12 years, the most is 20. The reason why these children die is due to an abnormal LMNA gene. This gene is what causes lamin A production which influences the shape of the nucleus. A normal nucleus is circle like, however a corrupted nucleus is extremely distorted. Since the nucleus is unstable cells die prematurely. Interestingly enough this disease is autosomal dominant. In basic genetics a heterozygous person would be affected by the dominant gene, and in Hutchinson-Gilford Progeria case they would not be able to pass on that dominant gene. The disease has cropped up in families with no history of Hutchinson-Gilford Progeria whatsoever, and scientists are still learning about this rare disease.

The most common genetic disease is Cystic Fibrosis. A mutation in the gene that causes the consistency in the digestive fluids to be thick and sticky instead of thin and slippery. The slippery digestive juices allow the food to pass through the digestive system easily, however when the fluid becomes thick it acts more as a plug than a lubricant. Sweat and mucus is also affected by the the mutated gene, and the pancreas and lungs are highly affected. The gene is recessive, and therefore two recessive alleles are required to cause Cystic Fibrosis. About a thousand people are diagnosed with Cystic Fibrosis every year.

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