I live in a neighbourhood in which most families reside in independent houses. During the pandemic, the family that lives in the house adjacent to ours went to attend a wedding reception. Within the next few days, several — but not all — members tested positive for Covid-19. Many wondered why all were not infected.

When I had started to teach human genetics several decades ago, I used infectious diseases as examples of diseases with no genetic basis. Today, we know that this is incorrect. Specific genetic factors present in some members of the family enabled them to escape the infection.

We have a strong social structure. Members of a community often marry within the community. These social norms have resulted in variations among communities of frequencies of genetic factors that cause diseases. Most human diseases have a genetic basis. Scientists are conducting research to unravel their genetic bases. Such research is throwing up unforeseen ethical issues that deserve wide discussion.

Diseases that are due to a single defective gene, such as sickle cell disease or thalassaemia, run in families from one generation to another. Such diseases are, however, uncommon. Common ailments, such as heart disease or diabetes, run in families but not in a systematic way. This is because variants in multiple genes are jointly responsible for causing a common disease. The impacts of these variants on the disease are usually unequal. Gene variants associated with many common diseases have been identified. Most such diseases do not manifest at birth, but at a later age. Identifying the gene variants and estimating their impacts on a disease enable us to predict the chance that a person will get the disease later in life. Early prediction improves disease management.

Scientific research is providing better genetic risk tools that are beneficial to some communities. But not to all. The tools that work well in one community do not necessarily work well in other communities because the effects of individual gene variants on a disease vary among communities. Indians, Ethiopians, Americans, French and Australians are biologically similar in a broad sense but have different ancestries. Dissimilarity of ancestries has resulted in notable genetic dissimilarities among population groups. Thus, the genetic variants that contribute to asthma in white American children are not the same for African-American children. If information on the constellation of high-risk gene variants of white Americans is used to predict risk in an African-American child, the prediction will be incorrect. Incorrect risk predictions can widen health disparities among populations. When diverse populations are not included in genetic research, we learn less from the research; we also contribute to inequity.

There is also unfairness in genetic research. Researchers from high-income countries often collaborate with researchers from low- and middle-income countries. However, priorities for the research are set by HICs-researchers overlooking local needs. The outcomes of such collaborations are unfairly beneficial to HICs researchers.

Unfairness and inequity in research have attracted attention in recent times. The Cape Town Statement has recommended increasing diversity and inclusivity, encouraging fair practice (such as addressing local needs, equitable authorship), providing infrastructure to LMICs to enable them to conduct research locally, and recognising indigenous knowledge. It is now widely recognised that the conduct of science has to be based on some principles so that the results of scientific research benefit all of humanity.

In studies that aim to find genetic markers associated with diseases, the number of participating individuals who were of European descent was 86% in 2011; this percentage remained at 86% in 2021. Little wonder then that the Human Cell Atlas international consortium has emphasised “Creating a scientific culture that dissolves … systemic inequities by... seeking to increase representation...”

The time to act is now.

Partha P. Majumder is National Science Chair, Government of India