During a genetic counseling consultation, a patient is asked about their ethnic background. This helps us provide a more accurate risk assessment for a pregnancy to be affected with a given condition. Though everyone is a carrier of an estimated 6-10 recessive conditions (which does not typically pose a risk to that individual’s health), certain genetic conditions are more common in certain ethnic populations.
Many people may be aware that the carrier risk for:
Cystic fibrosis is more common in those of European descent (1 in 25) than in those of Asian descent (1 in 90).
Sickle cell anemia is more common in those of African American descent (1 in 10) than in those of European descent (1 in 625).
Tay-Sachs disease is more common in those of Ashkenazi Jewish descent (1 in 29) than in those of the general population (1 in 280).
But most people may not know that:
The carrier risk for Tay-Sachs is almost as high in the Cajun population (1 in 30) as it is in those of Ashkenazi Jewish descent.
The carrier rate for 3-Methylglutaconic Aciduria: Type 3 is particularly high (1 in 10) in those of Iraqi Jewish descent.
The carrier rate of Andermann Syndrome is particularly high in those of French Canadian descent.
I speak with approximately 30 patients per week and continue to be amazed at the ethnic diversity I encounter. Some may ask, “What if I am more than one ethnicity?” The answer: then all of your ethnicities are factored into a risk assessment.
So what if you don’t know your ethnicity? CarrierMap, an expanded carrier screen, tests for up to 311 conditions across over 115 ethnicities. While knowing your heritage may be helpful, it’s not a prerequisite to screening. In the end, carrier screening is not designed to determine one’s ethnicity. It is meant to offer information on reproductive risk, which is information couples of any background may appreciate as they think about growing their family.