Understanding Inheritance of Huntington's Disease

Huntington's Disease is a genetic disorder that affects the brain and leads to the progressive degeneration of nerve cells. It is caused by a mutation in a single gene and is inherited in an autosomal dominant pattern. This means that only one copy of the mutated gene, inherited from either parent, is sufficient to cause the disorder. In this assignment, you will explore the inheritance pattern of Huntington's Disease and determine if it is possible for two parents with the disease to have a child without it.

Write a Claim-Evidence-Reasoning (CER) essay to answer the research question: "CAN TWO PARENTS WITH HUNTINGTON'S DISEASE HAVE A CHILD WITHOUT HUNTINGTON'S DISEASE?" Use the information provided below to support your essay.

Background Information:

Huntington's Disease is caused by a mutation in the HTT gene, located on chromosome 4. It is an autosomal dominant disorder, meaning that an individual only needs one copy of the mutated gene to exhibit the disease. If a person has the disease, they have at least one parent who also carries the mutated gene. A person with Huntington's Disease can be heterozygous (Hh) or homozygous dominant (HH) for the trait. A heterozygous individual has one normal allele (h) and one mutated allele (H), while a homozygous dominant individual has two mutated alleles (HH).

Your essay should include:

1. At least one sentence for your claim. It should answer the research question in ALL CAPS above.

2. At least three Punnett squares (type these out in the essay without a box, but make the squares in the same form as a regular Punnett Square, the scoring component will catch if you have the right amount and types of information in them). Explain the parents genotype below each Punnett square. You only need to include genotypes the parents could have.

3. At least one sentence that explains how your evidence from the Punnett squares you made connect to your claim and support it.

Using the concept of autosomal dominant inheritance, explain whether it is possible for two parents with Huntington's Disease to have a child without the disease. Use the Punnett squares you made to illustrate your explanation and support your claim with evidence and reasoning.