How is the disease diagnosed?

An experienced neurologist will obtain the individuals medical history and intensively question the individual to rule out all other possibilities. Many neurologists also use a pedigree to determine whether the individual has Huntington's Disease or not. It is essential for the individuals to be truthful and reveal the family history. The doctors will question the individual about recent intellectual and emotional problems and will test the person's hearing, eye movements, strength, coordination, involuntary movements (chorea), sensation, reflexes, balance, movement, and mental status, and will most likely order many lab entries as well. In some cases, the physician may ask the patient to have a brain imaging test.

What are the chances of a person with this disease passing the disease to their offspring?

Unfortunately the chances are very likely. Huntington's disease is a dominant gene so even if a one parent is heterozygous and the other one is homozygous recessive, there is still a 50% chance for the offspring to inherit this disease. If the parent is homozygous dominant instead of heterozygous there is 100% chance for the offspring to inherit the disease.

In this example one parent is homozygous dominant(HH) and the other parent is not affected at all(hh). All the offspring would all be heterozygous(Hh) for this disease. Since Huntington's disease is dominant, all the offspring would have this disease.

In this example, one parent is heterozygous for Huntington's(Hh) and the other parent is not affected at all by Huntington's(hh). There is a 50% chance of the offspring inheriting Huntington's disease in which case they would be heterozygous.

How prevalent is the disease in the population (include statistics)?

Huntington's disease is considered to be a "rare" disease in the United States and only 30,000 people in the U.S are affected by it. An estimated 150,000 more are at risk of inheriting it from a parent. About 3-7 out of 100,000 people of European ancestry are affected by Huntington's Disease.

What are the possible genotypes of the parents?

The possible genotypes for a parent of a person affected by Huntington's Disease could be Hh or HH. Huntington's disease is autosomal dominant so only one copy of the defective gene is necessary to inflict the offspring with Huntington's Disease.

How does a person inherit this genetic disorder? Is it dominant or recessive? Is it genetic or chromosomal?

Huntington's Disease is a genetic disease that is passed from parent to child by a mutation. It occurs when a small sequence of DNA on chromosome 4 has several base pairs that are repeated many times.The normal gene has 3 DNA bases which all contain the sequence CAG. People with Huntington's Disease have this sequence repeating dozens of times. Over time in each successive generation, this sequence repeats itself even more. Huntington's Disease is autosomal dominant so only one copy of the defective gene is necessary to be passed down from the parent to child to inflict the child with the disease.

What is a Genetic counselor?

Genetic counselors are health professionals who work to help families to understand genetic disorders and to inform and aid those families. Some also find local services that can help the family. To be a genetic counselor you have to have a masters degree in that area as well as a baccalaureate degree in fields such as biology or biosciences, psychology, nursing, or genetics. Most genetic counselors also have atleast one undergraduate degree in genetics. Genetic counselors should be able to communicate well with their clients. They should be able to identify problems and inform their clients of the problem so that they will understand.