A simplified screening for alpha-thalassemia 1 (SEA type) using a combination of a modified osmotic fragility test and a direct PCR on whole blood cell lysates.
In order to provide a rapid method for identifying alpha-thalassemia 1 in a region with massive population and limited resources, we have tested a rapid screening strategy. Preliminary screening was done using a modified one tube osmotic fragility test (OF test) followed by RBC indices; Hb analysis and detection of alpha-thalassemia 1 with the Southeast Asian deletion (SEA type) were performed by PCR. One hundred and seventy-five adult Thai subjects were studied. Fifty-one of the 175 subjects (29.1%) were positive for a modified OF test. They all had significantly lower MCV and MCH but higher RDW-CV values as compared to the OF negative group. A successful identification of alpha-thalassemia 1 deletion using a direct PCR on cell lysates was demonstrated. Among the 51 OF-test-positive subjects, 7 were found to be alpha-thalassemia 1 carriers, 3 of whom were also carriers of Hb E. No alpha-thalassemia 1 was detected in the OF-test-negative group. A combination of a modified OF test and a direct PCR analysis on whole blood cell lysates would therefore provide an effective screening for alpha-thalassemia 1 in the regions where a program of prevention and control of the disease remains underserved.
Department of Clinical Chemistry, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
Sittichai
S
Panyasai
Patcharawadee
P
Sringam
Goonapa
G
Fucharoen
Kanokwan
K
Sanchaisuriya
Supan
S
Fucharoen
D000328:Adult; D001773:Blood Cells / Q000473:pathology; D006403:Hematologic Tests / Q000379:methods / Q000592:standards; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D009996:Osmotic Fragility; D016133:Polymerase Chain Reaction / Q000379:methods; D011237:Predictive Value of Tests; D013785:Thailand / Q000453:epidemiology; D017085:alpha-Thalassemia / Q000097:blood / Q000175:diagnosis*
D006454:Hemoglobins