Comparison of two screening methods, modified Hb H preparation and the osmotic fragility test, for alpha-thalassemic traits on the basis of gene mapping.
We evaluated 61 patients with two screening tests for alpha-thalassemia traits on the basis of endonuclease gene mapping. Comparing these two methods--the osmotic fragility test of the red cell and modified hemoglobin H inclusion staining for the sensitivity--we found that the latter was much superior to the former with 100% sensitivity in detecting heterozygous alpha-1 thalassemia and it was also specific as a confirmatory test for thalassemia traits. Red cell indices are still the basic screening tool and can be used together with modified Hb H inclusion staining. The osmotic fragility test was not better than the red cell indices and was not confirmatory. Besides the MCV, RBC, and discrimination functions, we found that RBC distribution width-standard deviation (RDW-SD) was consistently low in heterozygous alpha-1 thalassemia but not in heterozygous alpha-2 thalassemia. None of the above tests was shown to be really helpful in screening in the latter situation. We conclude that the modified Hb H inclusion staining is superior to the osmotic fragility test in screening of alpha-1 thalassemia.
Lin
C K
CK
National Yang-Ming Medical College, Taipei, ROC.
Yang
M L
ML
Jiang
M L
ML
Chien
C C
CC
Lin
H H
HH
Peng
H W
HW
D002872:Chromosome Deletion; D002874:Chromosome Mapping; D004909:Erythrocyte Indices; D005069:Evaluation Studies as Topic; D006580:Genetic Carrier Screening; D005914:Globins / Q000235:genetics; D006447:Hemoglobin H / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D009996:Osmotic Fragility; D013194:Staining and Labeling; D013789:Thalassemia / Q000097:blood* / Q000175:diagnosis / Q000235:genetics*
D005914:Globins; D006447:Hemoglobin H