lessons in diversity

Sickle cell anemia (Hb S) is a classic study in carrier status and recessive inheritance, but the beta-hemoglobinopathies are far more complex than they seem. This study highlights the diversity within this group of disorders, and within the ethnicities at risk.

The purpose of this study was to determine the positivity rate of carrier testing for several beta-hemoglobinopathies and to identify the value of pan-ethnic testing to detect such carriers.

We performed a retrospective analysis of 73,929 patients referred for carrier testing for β-globin (HBB gene) disorders.

What did we find?

  • Of the 73,929 patients, 1471 (2.0%) were positive for one or more HBB gene mutations.1
  • The African American population had the highest positivity rate (12%), and the positive results included all beta-hemoglobinopathies tested, not just sickle cell anemia.1
  • The positivity rate in other ethnicities was also significant — patients who reported Asian or other/mixed ethnicity had positivity rates up to 2%.1
Pan-ethnic carrier testing for beta-hemoglobinopathies
revealed unexpected carriers belonging to
understudied ethnic backgrounds.1
This research was presented at the 2018 Association for Molecular Pathology (AMP) Annual Meeting. Download the poster


  1. Holland et al. Characterization of beta-hemoglobinopathy results in a large population referred for carrier testing. Poster presented at AMP 2018. San Antonio, TX.