title: The molecular and hematological heterogeneity of alpha thalassemia.
abstract: A study of genotypes in alpha thalassemia and their corresponding hematological phenotypes has shown that alpha(+) thalassemia is the most frequent type encountered in a Sydney population. Phenotypes of heterozygous alpha(+) thalassemia (alpha alpha/-alpha) in adults or children differ little from normal and so the disorder is difficult to identify. In contrast, Hb Bart's (gamma 4) is a useful marker for alpha alpha/-alpha in cord blood samples. Abnormal phenotypes are present in homozygous alpha(+) thalassemia (-alpha/-alpha), heterozygous alpha(0) thalassemia (alpha alpha/--) and non-deletional alpha thalassemia. Therefore, detection by routine hematological studies should be possible. A less severe phenotype in -alpha/-alpha compared to alpha alpha/-- was found which is interesting since 2 alpha globin genes are lost in both instances.
mesh_terms: D000328:Adult; D001315:Australia; D002648:Child; D002874:Chromosome Mapping; D004247:DNA / Q000235:genetics*; D004262:DNA Restriction Enzymes; D005260:Female; D005838:Genotype; D006452:Hemoglobinometry; D006455:Hemoglobins, Abnormal / Q000032:analysis; D006801:Humans; D008297:Male; D010641:Phenotype; D013789:Thalassemia / Q000175:diagnosis / Q000235:genetics*
chemical_list: D006455:Hemoglobins, Abnormal; D004247:DNA; C030448:hemoglobin Bart's; D004262:DNA Restriction Enzymes