1. (Draw and label a picture of a neurone here)
Huntington’s Disease – a neurological disorder of the central nervous system that causes progressive degeneration of brain cells
6. Genetic Screening
3. Mutation
6. Gene Therapy
1. Affected Areas
(Draw and label a picture of a neurone here)
4. Mode of Inheritance
5. Treatments
2. Symptoms

3. 3. Mutation
A mutation of the Huntingtin gene on chromosome 4 causes ‘CAG’ to be repeated, over the normal level of 35 times. This increases the size of the protein made, which is then cut into smaller, toxic fragments. These bind together and accumulate in neurones. However, the exact science of how this occurs is unknown.

4. 4. Mode of Inheritance
HD is caused by a d_________ allele, so you need _ copy to express Huntingtons Disease.
A punnet square / genetic cross to show an affected heterozygous parent, with a unaffected parent: (use a ruler to draw a genetic cross here)

5. 5. Treatments
(From Fridays video, you should be able to write a couple of full sentences (not bullet points!) on CF treatments / ways it is managed)

6. 6. Gene Therapy

7. 7. Genetic Screening