BIRTH WEIGHT IN COUSINS

Abstract

Summary There is a significant positive correlation between the birth weights of maternal first cousins, but not between other first cousins. This is interpreted as evidence for the existence of a maternal genetic factor in the determination of birth weight. Using estimates of the correlation between birth weight in sibs, twins and first cousins, the contribution to the total variance in birth weight of such factors as foetal genotype, maternal genotype and environment are discussed.