ROCHESTER, Minn. — Mayo Clinic researchers have found that genetic testing can help identify people who carry inherited blood disorder traits, including individuals who may not otherwise know their carrier status. Earlier identification can create opportunities for genetic counseling, informed family planning and appropriate clinical follow-up.

Using genetic data from nearly 50,000 participants, Mayo Clinic researchers identified carrier traits for sickle cell anemia and beta-thalassemia at clinically significant levels. Published in Mayo Clinic Proceedings, the study shows how population-scale genetic testing may complement existing screening approaches and provide patients and clinicians with additional information about inherited health risks.

"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," says Nathaniel Miller, M.D., a Mayo Clinic family medicine physician and first author of the study, published in Mayo Clinic Proceedings.

Screening practices have evolved over time. All U.S. states screen newborns for clinically significant hemoglobinopathies such as sickle cell disease, but practices for identifying and reporting carrier status have varied, particularly for thalassemias. Some adults also were born before comparable newborn screening was available. The findings illustrate how genetic testing later in life may provide health information that was not available earlier.

Genetic testing provides additional insight into carrier status

Sickle cell anemia and beta-thalassemia are hemoglobinopathies — inherited disorders that affect hemoglobin, the protein in red blood cells that carries oxygen throughout the body. In sickle cell anemia, abnormal hemoglobin causes some red blood cells to become rigid, sticky and misshapen, which can slow or block blood flow. Beta-thalassemia reduces the body's production of hemoglobin and can lead to anemia. People with sickle cell trait or beta-thalassemia trait often have few or no symptoms, but they can pass the genetic change to their children.

The research used data from Tapestry, which enrolled more than 98,000 participants across Mayo Clinic between July 2020 and May 2024. The initiative generated whole exome sequencing data to support clinical care, research discovery and genomic education. Researchers analyzed genetic data from nearly 50,000 participants for variants associated with sickle cell trait and beta-thalassemia trait and compared those findings with diagnosis codes in participants' electronic health records.

Among 116 participants identified through genetic testing with sickle cell trait, 19 had a corresponding diagnosis code. Among 98 participants identified as carriers of beta-thalassemia, 47 had a corresponding diagnosis code. The differences illustrate how genetic testing can add information to a person's health history, particularly when carrier status may not have been identified through earlier screening. Researchers also found instances in which existing diagnosis codes did not correspond with the genetic findings. The authors say additional research is needed to understand these differences, which may reflect variations in historical screening, classification and documentation practices.

Moving toward earlier identification

The findings point to opportunities to develop clearer guidance for identifying hemoglobinopathy carrier status and determining when genetic testing and counseling may be appropriate. Primary care clinicians may be particularly well positioned to help identify people who could benefit from testing before pregnancy.

"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," says Isa Houwink, M.D., Ph.D., a Mayo Clinic family medicine physician and senior author of the study. "That creates an important opportunity for preconception counseling and informed family planning."

The research aligns with Mayo Clinic's broader Precure Research initiative, which focuses on developing tools and approaches to identify disease-related risk earlier, before symptoms emerge or conditions become more difficult to treat. Visit mayo.edu/research/precure for more information.

For a complete list of authors, disclosures and funding, review the study.

### 

About Mayo Clinic
Mayo Clinic is a nonprofit organization committed to innovation in clinical practice, education and research, and providing compassion, expertise and answers to everyone who needs healing. Visit the Mayo Clinic News Network for additional Mayo Clinic news.

Media contact:

• Julie Ferris-Tillman, Ph.D., Mayo Clinic Communications, newsbureau@mayo.edu

Related Articles