The M quadruplets: I. Probability of uniovular origin judged from qualitative traits

Abstract

SummaryThe M quadruplets have been regarded as monozygotic by all investigators who have studied them carefully. Previous authors have based their diagnosis on the description of the placenta, on early physical resemblances, and on qualitative features.The addition of blood group tests to the criteria now tends to confirm the earlier conclusion. From an extension of methods devised for use in twins, it appears that the probability that these quadruplets originated from more than one zygote is less than one per cent. However, some quantitative differences, especially in finger prints, require a more elaborate analysis, and such an analysis will be presented and discussed in a second article.