A population cytogenetic study of a common fragile site, fra(3)(p14), in a healthy population

A population survey of a common folate-sensitive fragile site, fra(3)(p14), was carried out on PHA-stimulated peripheral lymphocytes of 1,078 healthy subjects. Fra(3)(p14) was expressed more frequently in the younger than in the older, and in males than in females. It also showed some seasonal variation. The age difference of the expression frequency was also observed by aphidicolin treatment. A positive correlation of the expression frequency was found, though not so strongly, between both culture conditions of folate deprivation and aphidicolin treatment, These findings suggest that the inter-individual variation in the expressivity of common fragile sites is not only ascribable to chance, but to some physiological conditions of blood donors such as response rate of lymphocyte to PHA stimulation and blood concentration of folic acid.