COMPOUND HETEROZYGOSITY HB-S HB HOPE (BETA(136)GLY-]ASP) - A PITFALL IN THE NEWBORN SCREENING FOR SICKLE-CELL DISEASE

The presence of Hb Hope associated with Hb S may represent a pitfall ( false positive) in the neonatal detection of sickle cell disease by tw o of the most widely used analytical methods in screening programmes-i soelectric focusing (IEF) and high performance liquid chromatography ( HPLC). This example illustrates the need to improve analytical strateg ies to avoid unnecessary anxiety and summoning of families often from a cultural background in which testing of the father is difficult to o btain. It is suggested that using two independent HPLC procedures migh t improve the specificity of the screening strategies. Additionally, s imple procedures for detection of the most common mutations of the bet a globin gene on DNA extracted from dried blood specimens could be eas ily developed for the control of abnormal samples. These procedures co uld be introduced into the analytical strategy.