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Sickle Cell Disease.

TO THE EDITOR: The review of sickle cell disease by Piel et al. (April 20 issue)1 is timely and highlights the need to address the lack of research about this disease in sub-Saharan Africa. The authors rightly state that in the past two decades, childhood mortality has been reduced in sub-Saharan Africa, but the survival data cited by Piel et al. were derived from a singlesite study performed almost four decades ago.2