Genetic Counseling Case Study

Genetic Counseling
If I was a genetic counselor working with a couple who just had a child with Tay-Sachs disease, I would first explain that it is an inherited genetic disease. It would be important to explain the lineage of the disease and how if they were to trace their ancestry, it would most like trace back to European Jews. People of this decent have a 1 in 27 chance of being a carrier. Testing of the parents to see if they are carriers would not be necessary. I would explain that they are definitely both carriers because the only way to have a child with Tay-Sachs is to receive the defective gene from both parents and the two defective genes are now affecting each cell inside of their baby.
Furthermore, I would discuss the Tay-Sachs disease itself. I would explain to the couple that the disease is caused by a mutation of the hexosaminidase A (HEXA) enzyme that has been altered. Because the parents would not understand this – I would explain the function of the HEXA gene and how it is responsible for the breakdown of fatty substances in the brain. Explanation would also include

what happens when this gene is absent and how toxic levels of fatty substances building up in the brain will affects the nerve cells. When they HEXA enzyme is absent, toxic levels of the fatty substance are reached in the brain and the child will start displaying symptoms of the disease.
It is not impossible to have no family history of Tay-Sachs in a couple that are carriers of the disease. Many people can be carriers but it takes two carriers to both pass the gene to the fetus before the infant will get it. Even though both parents are carriers – only one can pass the gene on to the fetus. I would gently try to explain to the couple that since they both passed the defective gene to their infant, their baby would not survive to pass the disease on to future generations. The outcome for their child is inevitable and most die before the age of four.
It would be hard to explain to the couple that for the next few months, even up to six months or more, the child will appear healthy and normal. Symptoms of mental and physical deterioration will appear after that time. The child may become, unable to swallow and will need a feeding tube, may lose their hearing, eye sight, lose muscle mass and strength, and likely become paralyzed. Death is certain because as of now, there is no treatment or cure for the disease. Supportive treatments is the only care to ease the symptoms of Tay-Sachs and to extend life.
Knowing that their child will certainly die, they may try to have another child in the future.

As a counselor, it would be very important for me to explain the chances of their future children having the disease. Since both parents are known carriers now, there is a 1 in 4 chance of their children having Tay-Sachs disease. There is a 2 in 4 chance their child will be only a carrier. If the couple were to divorce and marry someone that has had genetic testing and is not a carrier, there would be no chance of having a child with the disease, but would still have a 2 in 4 chance of having a child that is also a carrier of the disease. Genetic and prenatal testing would help plan future pregnancies. Another option for the parent would be to implantation. The embryos tested and then when a healthy embryo is found not to have the disorder, it would be implanted for a hopefully healthy

baby.