Enhanced Genetic Testing Accuracy Through Local Ancestry Inference

Researchers at Texas Children's Neurological Research Institute (NRI) and Baylor College of Medicine have introduced an innovative tool within the Genome Aggregation Database (gnomAD) that significantly improves the precision of genetic testing. This breakthrough, detailed in their study published in Nature Communications, utilizes a technique called local ancestry inference (LAI). Unlike traditional methods that analyze the genome as a whole, LAI segments the genome into ancestry-specific regions, enabling a more detailed understanding of genetic variation across diverse populations.

This advancement is particularly impactful for admixed populations—individuals with ancestry from multiple continents such as African, European, or Indigenous American. Conventional genetic frequency estimates often average data across broad populations, which can obscure meaningful differences in specific ancestral backgrounds. By applying LAI, the research team was able to identify that many genetic variants previously considered rare are actually common within certain ancestry segments, leading to a potential reclassification of some variants from pathogenic to benign.

Dr. Elizabeth Atkinson, a lead researcher from Baylor College of Medicine, explained that refining allele frequency data to reflect ancestral nuances enhances the accuracy of genetic diagnoses and reduces misclassification risks. Over 80% of genetic sites analyzed in African/African American and Latino/Admixed American groups showed higher allele frequencies in at least one ancestral tract compared to previous global estimates.

The new ancestry-informed data set is now publicly accessible on gnomAD, providing clinicians, researchers, and genetic testing laboratories with a more precise tool for interpreting genetic variations. This approach underscores the importance of considering detailed ancestry in genetic analysis to achieve better patient outcomes and advance personalized medicine.

Ultimately, this development signifies a move towards a more nuanced approach to genetic diagnosis—recognizing the complex, multi-ethnic backgrounds of individuals rather than relying on broad racial or ethnic labels. As Dr. Atkinson emphasized, understanding these ancestral differences is crucial for delivering accurate, equitable healthcare.

Source: Medical Xpress