text_1: A high microerythrocyte count protects against severe anemia in homozygous alpha (+)- thalassemia trait subjects.
text_2: In addition, children homozygous for alpha(+)-thalassaemia require a 10% greater reduction in erythrocyte count than children of normal genotype (p = 0.02) for Hb concentration to fall to 50 g/l, the cutoff for SMA.