Much of what scientists know about how genetic differences affect health comes from studying populations outside Africa. This matters because genetic information is increasingly being used to understand disease, interpret genetic tests and, in some cases, guide treatment.Africa has the greatest human genetic diversity in the world, yet African populations remain poorly represented in global genomic research. A genome is the complete set of DNA carried by a person. Only about 0.15% of participants in genome-wide association studies, which look for links between genetic differences and disease, are from Africa. When most of the evidence comes from populations elsewhere, some findings can be harder to interpret for African patients. For example, researchers found that some genetic changes previously reported as causing an inherited heart condition in people of African ancestry were actually harmless. Those errors were easier to detect once more genetic information from people of African ancestry became available.A genetic test is not useful simply because it can read a person’s DNA. Doctors also need reliable information to understand what a genetic change means. Better information from African populations could, over time, help provide clearer diagnoses for some inherited conditions, give families better information about diseases that run through generations and improve our understanding of why people respond differently to some medicines. In a recent paper, my colleagues and I examined national genome projects across Africa and how they could help address this gap.I approach this question as a molecular geneticist at Muhimbili University of Health and Allied Sciences in Tanzania. My co-authors bring expertise in genetics, genomics and population health from Egypt, Tunisia, Senegal, Kenya and South Africa. In the paper, we show how national projects differ in scale and focus, and argue that no single approach will suit every country. We also make the case that sequencing must be accompanied by local expertise, responsible data governance and sustained investment if it is to improve healthcare.What are national genome projects trying to do?National genome projects study many genomes to build a better picture of genetic differences within a population and how some of those differences relate to health and disease.Several African countries are moving in this direction. Tunisia, Egypt and Senegal have national initiatives, while government-led projects in Tanzania, Kenya and South Africa are at earlier stages. Other countries have genomic studies that could provide a foundation for broader national programmes.The projects offer different lessons. Tunisia plans to study both people without known disease and patients with clinical conditions. That could help distinguish harmless genetic differences from those relevant to a patient’s illness. Egypt aims to study a much larger number of people and investigate common and rare diseases; its challenge will be to turn that scale into useful knowledge and healthcare capacity. Senegal aims to include people from 31 ethnolinguistic groups across all 14 regions, addressing the risk that a “national” dataset overlooks parts of the population.In Tanzania, Kenya and South Africa, national genome project efforts are at different stages of development. Our paper does not assess their implementation. As these projects develop, the same questions will matter: who is represented, how the data are governed, whether local expertise is strengthened and how findings could eventually improve healthcare.Initiatives such as Human Heredity and Health in Africa (H3Africa) have already helped develop laboratories, research skills and collaborations across the continent. National projects should build on this experience, but be designed around each country’s health priorities and resources, because no single model will suit every country. How could this affect patients and families?The aim is not to offer every person a genetic test. The value lies in building knowledge that is currently missing and developing the people and systems needed to use it.For a family affected by an inherited disease, better local information may make it easier to determine whether a genetic change is linked to disease. Research may also help doctors understand why some medicines work differently between people. For health systems, locally generated evidence can help researchers study diseases that matter to their own populations. These benefits are not automatic. Sequencing thousands of genomes will achieve little if countries cannot analyse the data, interpret the findings or translate useful discoveries into healthcare.Sequencing DNA is only the startNational genome projects need laboratories, computing systems, trained scientists and health professionals who can interpret genomic information. They also need clear rules on consent, privacy, storage and who can use genetic data. Governments and project leaders can begin by agreeing on the health questions the project should answer, involving communities in its design and setting rules for consent and data access before collecting samples. Budgets should cover training, secure data systems and the people needed to interpret results, as well as sequencing itself.People are contributing information that is deeply personal. They should know why their data are being collected, how they will be protected, who may use them and how the knowledge generated may benefit their communities. International collaboration will remain important, but countries should also have meaningful control over genomic data generated from their populations.Can African countries afford this?Many African health systems are already dealing with infectious diseases, shortages of health workers and rising numbers of people with cancer and cardiovascular disease. Genomics should not be presented as competing with these priorities.Countries do not all need very large genome projects. They can start at a scale they can sustain, focus on health problems that matter locally and expand as capacity grows. Regional cooperation can also help by sharing sequencing, data analysis and training capacity. Long-term funding matters too. Projects that rely only on short research grants may generate useful data but struggle to maintain staff and equipment once funding ends.What should success look like?The easiest way to describe a national genome project is by the number of people whose complete DNA it reads. But that should not be the main measure of success.For the public, the more important question is what changes because the project exists. Does it improve the interpretation of genetic tests? Does it help families affected by inherited disease get clearer answers? Does it generate evidence that can help improve treatment for African patients? And does it build local expertise and services that remain after the sequencing is finished?National genome projects will not transform healthcare overnight. Their value will depend on whether the data are translated into better knowledge, stronger health systems and services that people can actually use. African genomic data are valuable to global science, but the countries and communities contributing those data should also benefit.If these projects are built around local health needs, public trust, strong institutions and sustained investment, they can help close an important gap in the evidence used to understand health and disease. For ordinary people, that is what should matter most: not simply that more African genomes are sequenced, but that the knowledge generated ultimately helps improve healthcare for African populations.Mohamed Zahir Alimohamed is a co-founder and Secretary General of the Tanzania Human Genetics Organisation.