AP BIOLOGY

Detailed explanation-1: -Huntington’s disease is an autosomal dominant disorder, which means that a person needs only one copy of the nontypical gene to develop the disorder. With the exception of genes on the sex chromosomes, a person inherits two copies of every gene-one copy from each parent.

Detailed explanation-2: -Huntington’s disease is autosomal dominant, meaning inheritance of just a single copy of an abnormal chromosome from a biological parent is enough to cause it. If one parent carries the abnormal gene, each of their biological children has a 50 percent chance of Huntington’s disease inheritance.

Detailed explanation-3: -Mutations in the HTT gene cause Huntington disease. The HTT gene provides instructions for making a protein called huntingtin.

Detailed explanation-4: -Huntington’s disease is caused by a faulty gene. Cells in parts of the brain are very sensitive to the effects of the faulty gene. This makes them function poorly and eventually die. A parent with the Huntington’s disease gene has one good copy of the gene and one faulty copy.