Several severe genetic diseases are commonly or almost exclusively linked to certain ethnic populations. As populations become more diverse, healthcare workers must learn the complete ethnic backgrounds of patients as well as their partners before couples have children. Many of these genetic diseases are "recessive," which means they require a gene from both the mother and the father for the disease to be present in the child. Neither parent may have the disease, but they may each carry a recessive gene for the disease and when they pair their genes, the child will receive a disease-laden gene from each parent.
What are the most common ethnically related diseases?
• Tay Sach's disease. Causes mental retardation, blindness, seizures, and death, usually by the age of 5. This is most commonly found in Jewish people of Eastern European descent (Ashkenazi Jews), French Canadians, and Cajun people.
• Sickle Cell disease. Causes malformation of the red blood cells, which leads to chronic anemia and episodes of severe pain. This disorder is most commonly found in African Americans.
• Cystic fibrosis. Leads to the formation of thick, abnormal mucous that makes it difficult for the patient to breathe and digest food. It is most commonly found in those of northern European descent (Caucasians).
• Beta thalassemia. Affects the production of hemoglobin, the part of the blood that carries iron, leading to anemia and blood clots. The most commonly affected are people from the Mediterranean countries, North Africa, the Middle East, India, Central Asia, and Southeast Asia.
How do you prevent these diseases?
If you find that you are in an ethnic group that is at risk for a disease, or if you know that you have a certain genetic disease in your family history, it would be wise to go for genetic counseling prior to you or your partner getting pregnant. You might decide to have yourself and your partner tested for a concerning gene. Or, you might choose to have testing done on the fetus once you become pregnant. You should be aware of the disease possibilities so that if your baby demonstrates any concerning signs or symptoms, you get prompt and appropriate care for your infant. If your health care provider asks you what your ethnicity is, make sure you list every piece of your heritage.
How to collect family history
Your family history holds key information about your past and clues to your future health. Many of your physical traits (such as eye colour, hair colour, and height) are inherited. So, too, are risks for certain genetic conditions and health problems such as heart disease, diabetes, and some cancers.
You can collect your family history by talking to your relatives. Start with your parents if they are living. Older relatives are often good sources of information. If you are adopted, you may be able to learn some of your family history through the parent(s) that adopted you or from adoption agency records.
Additional sources of information
Check whether your family has existing family trees, charts, listings of family members. Information may be recorded in baby books, birthday date books, or a family bible. It is important to collect accurate information, so verify the medical history whenever possible. One way to record a family history is by drawing a family tree called a pedigree. Begin by writing down the medical and health information on yourself, your brothers and sisters, children and parents. Then go back a generation at a time. Include nieces and nephews, aunts and uncles, grandparents and cousins.
For each relative, try to write down as many of these items as possible:
•Age or date of birth/death
• Medical problems such as cancer, heart disease, diabetes, asthma, mental illness, high blood pressure, stroke, kidney disease, alcoholism etc.
• Birth defects such as spina bifida, cleft lip, heart defects, others.
• Learning problems, mental retardation.
• Vision loss/hearing loss at a young age.
• For family members with known medical problems, jot down if they smoked, their diet and exercise habits, and if they were overweight.