Case 2: Testing of Children

1. Case 2: Testing of Children Candice Candelori Kelly Hare CT Harry Becca Paczkowski

2. 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 Case 2: Huntington’s Disease

3. 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

4. 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

5. 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.