Abstract

Reasons are given for suggesting that individuation of the human embryo does not begin until the primitive streak forms at about the fourteenth day after conception; this view, though contested by many, is held by very many committed Christians of all denominations. In the conceptus or pre-embryo, after the formation of a blastocyst at about four-five days after fertilisation, biopsy of a single cell from the outer layer of cells (which later can form the membranes and placenta) can be used to determine the sex of the conceptus and will ultimately be used to detect the presence of an abnormal gene such as that for Duchenne-type muscular dystrophy, without detriment to development of the basal cell mass from which the embryo forms. The potential benefits in the prevention of inherited disease are profound.