More than 192, 000 U.S. women get breast cancer diagnoses each year, and about 5 to 10 percent of those cases are a hereditary form of the disease, according to the National Cancer Institute.

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Huntington's disease is an hereditary neurological disorder of the central nervous system that causes progressive degeneration of cells in the brain, slowly impairing a person's ability to walk, think, talk and reason.

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He has Sargardt's disease, which is a hereditary condition.

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Research published in the prestigious medical journal, The Lancet, indicates that a regular dose of aspirin may not only stave off heart disease but also cut the risk of developing hereditary cancer in half.

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If monosygotic twins are a whole lot more likely to display similar patterns of disease, then that would suggest it is strongly hereditary.

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