in the full (homozygous) disease life expectancy is shortened, in fact it is near-fatal in pre-modern societies. sir cyril clarke said (referring to east africa in the 1960s) "almost all the children (with sickle-cell disease) will die in infancy".p25. studies in the modern u.s.a. report an average life expectancy of 42 years for males and 48 years for females.