Silent β-thalassemia mutations at -101 (C>T) and -71 (C>T) and their coinheritance with the sickle cell mutation in Bahrain.

Silent β-thalassemia (β-thal) is a group of mutations affecting the β-globin gene that cannot be differentiated in heterozygote states from normal conditions by using conventional criteria for the diagnosis of β-thal trait. Here we report the existence of two silent β-thal mutations in the population of Bahrain, one at -101 (C>T) and the other at -71 (C>T). We screened 126 healthy individuals with high-normal Hb A2 levels and found a frequency of 23.