The Importance of Completing the Ancestry Questionnaire in DNA Analysis

Why should you complete the ancestry questionnaire when your DNA is already being analyzed? It's a valid question, and the answer lies in the complexities of genetic inheritance and the accuracy of ancestry determination.

Enhancing Chromosome Assignment: Your DNA test results include readings from both chromosomes inherited from your parents—one from your mother and one from your father. However, without your parents' DNA, it's challenging to determine which genetic read aligns with which parent. While algorithms can predict this to some extent, they can produce mosaics—a blend of both parental DNAs. This can be particularly problematic for individuals with mixed ancestry (e.g., part Chinese, part Italian), leading to scrambled chromosomes that reduce the accuracy of ancestry models.

Improving Ancestry and PRS Model Accuracy: By completing the ancestry questionnaire, you provide crucial data that helps assign DNA segments more accurately to your maternal and paternal chromosomes. This doesn’t directly alter the initial identification of DNA segments in our ancestry algorithm, which compares your DNA against 33 diverse populations. However, it enhances the algorithm’s ability to organize these segments correctly across your chromosomes, particularly in the final analysis stages.

Adjusting Predictive Risk Scores (PRS): The information from the questionnaire also aids in refining Predictive Risk Scores for various health conditions. For instance, knowing your specific ethnic background allows us to compare your DNA against reference DNA from the same ethnicity, adjusting your health risk scores accordingly.

Uncovering Deep Ancestral Roots: Our algorithm doesn't just look at recent generations, such as grandparents; it delves into your lineage across hundreds of years. Sometimes, it may reveal unexpected elements of your ancestry.

Completing the ancestry questionnaire ultimately enhances the precision and personal relevance of your DNA analysis, ensuring that the insights you receive are both accurate and reflective of your unique genetic heritage. This step is crucial for anyone looking to obtain the most detailed understanding of their ancestry and health predispositions.