| |
|
Ethnic Diseases Screening
Some recessive genetic conditions are known to occur with an increased frequency in certain ethnic groups. When both parents are carriers of the same recessive disease, there is a 1 in 4 (25%) chance that the pregnancy will have the disease, a 1 in 2 (50%) chance that the pregnancy will be a carrier, like the parents, and a 1 in 4 (25%) chance that the pregnancy will not be a carrier or have disease.
(Insert Punnet square or parent-child inheritance diagram here)
When there is no family history of a disease, there is still a risk for recessive diseases based on your ethnicity. Carrier status for a recessive disease is commonly passed silently from generation to generation. Frequently, carriers are identified only by a specific genetic test. Following is a table listing some of the more common diseases and carrier frequencies in different ethnic groups
Ethnic Group |
Disease |
Carrier Frequency |
Ashkenazi Jewish
|
Canavan Disease |
1 in 40 (2.5%) |
Tay Sachs Disease |
1 in 30 (3%) |
Cystic Fibrosis |
1 in 25-29 (4%) |
Familial Dysautonomia |
1 in 30 32 (3%) |
African American / West Africa |
Sickle Cell Anemia |
1 in 6 – 12 (8 - 16%) |
Other Hemoglobinopathy |
- 1 in 30 – 75 (up to 3%)
|
European Caucasians |
Cystic Fibrosis |
1 in 25 - 29 (4%) |
Mediterranean / South Asian |
Beta Thalassemia |
1 in 20 - 30 (3 - 5%) |
SE Asian (Loas, Vietnam, Thailand) |
Alpha Thalasssemia |
1 in 20 (5%) |
Beta Thalassemia |
1 in 30 (3%) |
|
