Monte Carlo simulation on the effect of different approaches to thalassaemia on gene frequency

We used computer simulation to determine variation in gene, heterozygous and homozygous frequencies induced by 4 different approaches to thalassaemia. These were: supportive therapy only; treat homozygous patients with a hypothetical modality phenotypically only; abort all homozygous fetuses; and prevent marriage between gene carriers. Gene frequency becomes constant with the second or the fourth strategy, and falls over time with the first or the third strategy. Heterozygous frequency varies in parallel with gene frequency. Using the first strategy, homozygous frequency falls over time; with the second strategy it becomes constant; and with the third and fourth strategies it falls to zero after the first generation. No matter which strategy is used, the population gene frequency, in the worst case, will remain constant over time.