Chromosome anomalies among livebirths.

Abstract

A considerable proportion of heritable disease in man is a consequence of the presence of constitutional chromosome anomalies. These are anomalies which are present in the germ cell or which arise during the early cleavage divisions of a zygote, so that all, or a substantial proportion, of the cells carry the abnormality. The types and consequences, frequencies, heritability and mutation rates are all discussed.