Cloning, clones and clonal disease

In the past, cloning has been familiar to plant breeders because many plant s can be easily reproduced in this way, bypassing the lengthy process of cr oss-fertilisation. Recently, the concept of cloning has become popular in h uman biology and medicine on two accounts. First, individual genes can be c loned from the enormous complexity of the DNA that makes up the human genet ic material. It is expected that, within a few years, all the estimated 100 ,000 human genes will be isolated by this approach. This should make ii pos sible to identify all the genes that determine the individual characteristi cs of human beings, including those responsible for causing human diseases or for making people more or less susceptible to pick up diseases from the environment. Cloned genes made into pharmaceutical products are already in use for treating a variety of diseases, from hormonal deficiencies to certa in types of anaemia.