| − | '''Huntington's disease''', or '''Huntington's chorea''', is a degenerative [[brain]] disorder caused by a [[dominant]] allele. This means that if one parent has the allele, each child has a 50% chance of inheriting it. Unlike most dominant diseases, Huntington's disease is not excluded by [[natural selection]] because symptoms usually do not appear until mid-life <ref>http://www.genome.gov/glossary.cfm?key=Huntington%27s%20disease</ref>, after the carrier has already had children. The disease is named after Dr. [[George Huntington]], who first recognized the disease and its hereditary nature in 1872 <ref>http://www.whonamedit.com/doctor.cfm/966.html</ref>. It has been traced in numerous families in Brazil, England, and America. Genetic testing is available; however, many possible carriers opt to not test so they will not have to live with knowing that they will get Huntington's Disease later in their lives. | + | '''Huntington's disease''', or '''Huntington's chorea''', is a degenerative [[brain]] disorder caused by a [[dominant]] allele. This means that if one parent has the allele, each child has a 50% chance of inheriting it. Unlike most dominant diseases, Huntington's disease is not excluded by [[natural selection]] because symptoms usually do not appear until mid-life,<ref>http://www.genome.gov/glossary.cfm?key=Huntington%27s%20disease</ref> after the carrier has already had children. The disease is named after Dr. [[George Huntington]], who first recognized the disease and its hereditary nature in 1872.<ref>http://www.whonamedit.com/doctor.cfm/966.html</ref> It has been traced in numerous families in Brazil, England, and America. Genetic testing is available; however, many possible carriers opt to not test so they will not have to live with knowing that they will get Huntington's Disease later in their lives. |