A total of 1,500 pairs of adult twins,600 monozygotic and 900 dizygotic,were studied to estimate the concordance for a childhood cancer.In the 600 monozygotic twins,40 of the pairs were concordant for the disease,60 of the pairs were discordant for the disease,and neither twin had the disease in the remaining 500 pairs.In the 900 dizygotic twins,30 of the pairs were concordant for the disease,120 of the pairs were discordant for the disease,and neither twin had the disease in the remaining 750 pairs.What is the most reasonable conclusion to be drawn from these data?

Question

Quizplus · Accepted Answer

The concordant rate of the disease in twin pairs with at least one affected member among monozygotic twins is 0.4,40 divided by 100.And the concordant rate of the disease in twin pairs with at least one affected member among dizygotic twins is 0.2,30 divided by 150.The concordance rate is higher in monozygotic twins than in dizygotic twins,which indicates that there is some role of genetic factors in childhood cancer."Genetic factors are unimportant in the etiology of childhood cancer" is not correct,because data suggest that genetic factors are important in the etiology of childhood cancer."The incidence of childhood cancer within monozygotic twins is higher than dizygotic twins" and "The prevalence of childhood cancer within dizygotic twins is higher than monozygotic twins" are not correct.Based on given information,we cannot calculate and compare the incidence rate or prevalence of childhood cancer."Environmental factors are the major determinants of child food cancer" is not correct.It is hard to say that environmental factors are the major determinants of childhood cancer.

A Total of 1,500 Pairs of Adult Twins,600 Monozygotic and 900