Abstract
This study refers to the quantitative hemoglobin (Hb) phenotype of a 19-year-old female with Hb Valletta [β87(F3)Thr→Pro] in association with Hb Marseille/Long Island [β2(NA2)His→Pro; (–1)Met-(+1)Val-(+2)Pro-Leu] and a normal Hb electrophoretogram. The data serve to alert investigators to the possibility that relatives with apparently normal Hb phenotypes may be transmitting mutant alleles and suggest methods for identification.