Researchers at Texas Children’s and Baylor College of Medicine have pioneered a new tool to enhance the accuracy of genetic testing. By refining allele frequency estimates for diverse populations, this breakthrough is set to revolutionize patient care globally.
Researchers at Texas Children’s Duncan Neurological Research Institute (NRI) and Baylor College of Medicine have developed a new tool designed to boost the accuracy of genetic testing. This innovation, which draws from local ancestry inference (LAI), marks a significant leap forward in personalized medicine, offering more precise diagnoses for diverse patient populations.
The novel approach involves breaking down the human genome into ancestry-specific segments. This allows for a more detailed analysis of genetic differences that could be crucial for accurate diagnoses.
“This research updates our genomic resources to better reflect the full spectrum of genetic variation,” senior author Elizabeth Atkinson, an assistant professor in the Department of Molecular and Human Genetics at Baylor College of Medicine and principal investigator at the NRI, said in a news release. “By refining allele frequency estimates for admixed populations, we can improve the accuracy of genetic diagnoses and reduce the risk of misclassification — ultimately benefitting patients across all backgrounds.”
The study, published in the journal Nature Communications, addresses a critical gap in genetic testing, particularly for individuals of mixed ancestry.
Traditionally, genetic variant frequencies are averaged across large groups, which may not accurately reflect the genetic backgrounds of people with ancestry from multiple continents, such as African/African American or Latino/Admixed American populations.
Using the LAI method, Atkinson’s team segmented genomes to trace different continental ancestries, calculating how common each genetic variant is within these segments.
This approach revealed that many variants previously considered rare are actually more common within certain ancestry backgrounds.
“These differences are not just academic,” Atkinson added. “They have clinical consequences.”
The researchers discovered that in the African/African American and Latino/Admixed American groups, over 80% of genetic sites had a higher frequency in at least one ancestry-specific tract than previously reported.
In some instances, this information reclassifies variants, pushing them past thresholds set by the American College of Medical Genetics and Genomics (ACMG) to determine whether they are benign
This can drastically improve diagnostic accuracy.
The new ancestry-specific data has been integrated into the Genome Aggregation Database (gnomAD), making it accessible to researchers, clinicians and genetic testing laboratories globally.
This enhanced data set aims to refine the interpretation of genetic variations, aligning with a more nuanced understanding of ancestry in patient care.
“Ancestry is complex, and putting a single label on patients is not the most accurate way to diagnose them,” concluded Atkinson. “With this research, we are moving toward a more nuanced consideration of ancestry.”
Source: Texas Children’s