Asian immigration and public health in California: Thalassemia in newbornsin California

Purpose: This study reviews Asian immigration in California and the effect it has had on public health in the state in terms of genetic disease detect ion. This is documented in terms of the numbers of cases of thalassemia det ected, including Hemoglobin (Hb) E/beta -thalassemia, beta -thalassemia maj or, and Hb H disease. Patients and Methods: California has been screening all newborns for hemogl obinopathies since 1990 and tests approximately 530,000 newborns per year. Samples are collected on filter paper during the first 1 to 2 days of life and sent to one of eight contract laboratories. The screening methodology i s cation exchange high-performance liquid chromatography. Confirmatory test ing is performed at Children's Hospital Oakland hemoglobin laboratory using a variety of methods. Results: Approximately five to seven cases each of Hb E/beta -thalassemia a nd beta -thalassemia major are detected annually. Most cases are of Southea st Asian origin. Prevalence rate of Hb E/beta -thalassemia among Southeast Asians is approximately 1 in 2,200 births. A pilot program for Hb H disease screening was successful and this disorder has now been incorporated in ne wborn screening, detecting approximately 40 cases per year. Conclusions: Increases in Asian immigration and births in the U.S., particu larly California, have been dramatic during the past 10 years and have led to detection of previously rare diseases like Hb E/beta -thalassemia. It ha s also changed the way other thalassemic disorders are viewed, such as Cool ey anemia, which previously affected mainly individuals of Mediterranean or igin. Now, most affected patients are of Asian origin.