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.