The increased knowledge of human genetics may eventually lead to forms of genetic discrimination. As scientists attempt to unravel DNA sequences in order to further understand the mental and physical composition of the individual, the ability to identify each person's genetic shortcomings in advance of any detected disabilities increases. Some fear such identification may lead to discrimination in employment, academic admission and insurance benefits. Others highlight the devastating effect on people's lives of learning they have a high risk of a fatal and incurable disease. At present there are no laws, nor prospects of legislation, to address these issues.
Genetic discrimination can also become conflated with racial discrimination. A robust body of scholarship recognizes the existence of geographically- based genetic variation in our species, but shows that such variation is not consistent with biological definitions of race. Nor does that variation map precisely onto ever changing socially defined racial groups. This is not to say that genetic variation is unimportant; it is, but it does not follow racial lines.
Even "male" and "female" has important limitations. While these categories help us to know and care for many human beings, they hinder our capacity to know and care for the millions of human beings born into this world not clearly "sexed.’ Further, overemphasizing the importance of the X and Y chromosomes in determining sex prevent us from seeing the other parts of the genome involved in sex.
Genetic screening for disposition to certain diseases has been common in many countries for around 30 years, beginning with the rhesus tests carried out on pregnant women to avoid stillbirths from blood incompatibility. Most babies now have a heel prick at six days to test for such genetic disorders as PKU, hypothyroidism, sickle cell anaemia and cystic fibrosis. Genetic scientists associated with the international Human Genome Project hope to "map" the approximate 100,000 genes which define an individual by the year 2003. As molecular techniques are developed, specialists suggest it will not be long before testing covers 100 different single-gene disorders.
In 1994, it was revealed by a French research team that the Apo4 gene comes in three varieties: E2, E3 and E4. The E2 gene is associated with longevity; among French centenarians, significantly higher E2 levels were found compared with a control group of adults. Version E4 was found to be significantly unlikely to be in the blood of centenarians, and this version of the gene is also linked to Alzheimer's disease. It is estimated that between 2 and 3% of people have one or two copies of the E4 gene, giving them a 45% and 90% chance, respectively, of having Alzheimer's disease by age 75.
In the mid-1980s only a handful of companies were using genetic tests. By 1996, some 5 percent of corporations in the USA were examining the genes of employees. It is believed that it will soon be possible to calaculate an individual's susceptibility to common disorders such as diabetes, ischaemic heart diseases, asthma and rheumatoid arthritis leading to further pressures from employers and insurance companies.