Autosomal Dominant

Autosomal Dominant - The gene is on chromosome 17....

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Autosomal Dominant Severe dominant diseases are rare because carriers die before they get a chance to reproduce and pass on the disease to their offspring. Heterozygotes (Aa) have the trait. Children with the trait have at least one parent that has the trait. Two parents with the trait can produce a child that does not have the trait. Both males and females are affected equally. Neurofibromatosis (NF) Neurofibramatosis is actually three separate genetic diseases that cause benign tumors to grow on nerves. People with this gene typically have 6 or more large tan spots on the skin which may increase in size, number and darkness. There may be learning disabilities and hyperactivity. The disease is usually mild but may be severe causing deformities and even death. The incidence is 1 in 3000 newborns.
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Unformatted text preview: The gene is on chromosome 17. Huntingtons Disease The brain cells of Huntington's victims slowly degenerate, producing jerking muscles, slurred speech, swallowing difficulty, loss of balance, mood swings, reasoning and memory loss, incapacitation, and eventually death (usually from pneumonia or heart failure). The onset of Huntingtons disease is typically 35 to 45 years. It is caused by a repeated DNA sequence (AGC). The normal allele has 11-34 copies; affected people have 42 - 120 copies. The severity and time of onset depends on the number of repeats. People who are most at risk inherit the gene from their father. This is an example of genomic imprinting. The gene is on chromosome 4. A diagnostic test is available....
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