The Editor, Sir:

Why is it so hard to believe that a high percentage of persons born from a genetic pool with certain physical attributes will not dominate?

Jamaicans are predominantly of West African ancestry. Approximately 98 per cent of West Africans have the RR or RX copy of the Actinin three gene associated with sprinting dominance. Jamaicans are built for short explosive running. They are heavier than the East Africans.

Right environment

You need to be light weight to be able to maximise your oxygen or respiration efficiency over any sustained distance. Since we are genetically predisposed to be dominant at sprinting, when the right environment is created, the genes will be switched on and we will excel at the Olympics.

This interaction of the gene and the environment is called Gene Environmental Interaction (GXE).

The same goes for diabetes, if you inherited the genes from your parents and you eat fatty foods and do not exercise, the diabetes will be manifested. In some families, the manifestation is so great that it is termed increased penetrance. In layman terms many more persons have the diabetes than were expected to.

Diabetes and sprinting

Genes are associated with both fitness and sickness. Jamaica's incidence of diabetes is very high. One of the very genes linked to diabetes, the angiotensin converting enzyme gene is also implicated in the sprinting mechanism.

Why then is it so hard to believe that a gene might increase prowess or bring distress?

I am, etc.,

RACHEL IRVING

rachael.irving@

uwimona.edu.jm

University of

the West Indies

Mona, Kingston 7

Via Go-Jamaica