Commentary on 'The modifying effect of Xmn1-HBG2 on thalassemic phenotype is associated with its linked elements in the beta globin locus control region, including the palindromic site at 5′ HS4' by M. Neishabury et al.

摘要

Because of the milder phenotypes often associated with relatively high levels of fetal hemoglobin in patients with different forms ofbeta thalassemia or sickle cell anemia there is major interest in the factors that regulate the switch from fetal to adult hemoglobin and how this may be modified for therapeutic purposes. Recently there has been considerable progress in defining the loci or genomic regions that may be involved in the regulation of the switch from fetal to adult hemoglobin [1-3]. The first polymorphism of this kind, which in fact was discovered many years ago [4], is the C/T polymorphism at position -158 to the HBG2 locus, sometimes termed Xmnl -HBG2. Despite a great deal of work the functional significance of this mutation has never been clearly defined and it is possible that it reflects a marker in linkage disequilibrium with a functional polymorphism elsewhere in thebeta globin gene cluster.