RT Journal Article SR Electronic T1 Heterozygote advantage. JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 343 OP 344 DO 10.1136/adc.52.5.343 VO 52 IS 5 A1 Edwards, J H YR 1977 UL http://adc.bmj.com/content/52/5/343.abstract AB