Genetic Testing Offers Opportunities for Earlier Blood Disorder Carrier Identification

People with sickle cell trait or beta-thalassemia trait often have few or no symptoms but can pass the genetic change to their children. Carrier identification has varied over time, leaving some adults born before comparable newborn screening was available unaware of their status. New findings suggest that genetic testing may help identify these carriers earlier.

Mayo Clinic (Rochester, MN, USA) researchers evaluated genetic testing for identifying carriers of sickle cell and beta-thalassemia traits. Both are associated with hemoglobinopathies, inherited disorders affecting hemoglobin, the oxygen-carrying protein in red blood cells. In sickle cell anemia, abnormal hemoglobin can make red blood cells rigid, sticky, and misshapen, whereas beta-thalassemia reduces hemoglobin production and can lead to anemia.

The study drew on Tapestry, an initiative that enrolled more than 98,000 participants across Mayo Clinic between July 2020 and May 2024 and generated whole-exome sequencing data to support clinical care, research discovery, and genomic education. Using data from nearly 50,000 participants, researchers searched for variants associated with sickle cell trait and beta-thalassemia trait, then compared their findings with diagnosis codes in electronic health records.

Genetic testing identified 116 participants with sickle cell trait, of whom only 19 had a corresponding diagnosis code. Similarly, 98 participants carried beta-thalassemia trait, but only 47 had a matching code. The team also found instances in which existing diagnosis codes did not align with genetic findings. The authors noted that further research is needed to understand these discrepancies, including the roles of historical screening, classification, and documentation practices.

Published in Mayo Clinic Proceedings on October 27, 2026, the findings highlight opportunities for clearer guidance on identifying hemoglobinopathy carriers and determining when genetic testing and counseling may be appropriate. This emphasis on earlier risk identification also aligns with Mayo Clinic’s Precure Research initiative, which develops tools and approaches to recognize disease-related risk before symptoms emerge or conditions become more difficult to treat.

“If we can identify carrier status earlier, we have more opportunities for reproductive counseling, appropriate preventive care and helping patients understand what these findings may mean for their families,” said Nathaniel Miller, M.D., a Mayo Clinic family medicine physician and first author of the study.

“From a primary care and population health perspective, the goal is to identify carrier status early, ideally before pregnancy, because many people don't know they are carriers. That creates an important opportunity for preconception counseling and informed family planning,” said Isa Houwink, M.D., Ph.D., a Mayo Clinic family medicine physician and senior author of the study.

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