Case 2: Testing of Children

Candice Candelori

Kelly Hare

CT Harry

Becca Paczkowski

Case 2: Huntington’s Disease Grandfather died of HD--had

two children, son already affected by HD

daughter now age 40, recently divorced, and in financial dismay is concerned about HD fate and possibility of children having the disease– wants genetic testing for

children to see which she should send to college with limited financial resources

+,52

42 40

16 14

I

II

III

Prognosis of Huntington’s Disease

an autosomal dominant disease caused by a CAG triplet repeat sequence; age of onset is in mid-life (30s-40s)

not caused by random mutations, almost always the result of one affected parent due to the autosomal dominance and low chance of incomplete penetrance

symptoms: personality changes, memory loss, motor problems– 10 cases for every 100,000 people in the US (30,000

people total)– illness usually lasts 15-20 years– death often due to pneumonia because patient can

not cough well enough to clear chest– no known cure

Final Thoughts who is affected?

– children of mother; test will decide their fate in terms of a college education

consultation advice

– mother’s decision whether or not to be tested

– mother shouldn’t decide if children are tested or fate if they are tested

– according to pedigree, mother has 50% chance of developing HD

• means that children may have 50% or 0% chance of developing HD depending on mother’s genotype

• mother should investigate more about HD to understand the risks and implications involving her family before undergoing genetic testing

References http://neuro-chief-e.mgh.harvard.edu/mcmenemy/

facinghd.html#contents http://www.hdfoundation.org/ Gelehrter, Thomas D. Principles of Medical Genetics.

Williams & Wilkins. Balitmore 1998.