Genomics changes the way health systems provide care across the world [1]. Genomic medicine is an emerging interdisciplinary medical specialty that involves using genomic information about individuals and their family members as part of their clinical management [2]. As such, it has great potential to offer insights into how humans’ genetic variation can affect their health, prevention options and treatment responses [3]. Over the past thirty years, the revolution in genomic technologies has fostered an increased understanding of the molecular mechanisms of diseases. It has also led to the widespread use of genomic information across all medical specialties as part of clinical care to determine disease risk, diagnosis and prognosis as well as to select treatment options [3]. This supported the development of precision medicine, which aims to tailor disease prevention, diagnosis and treatment by considering differences in people's genes, environments and lifestyles. It is expected that genomic technologies will soon not only predict diseases and optimise diagnoses and treatment options for individuals but also potentially help eliminate some genetic disorders entirely with gene-editing technologies [4].

Genomic medicine in Belgium has been well-established since 1987, with eight Centres for Human Genetics (CHGs) dedicated to both clinical and laboratory activities. Notably, substantial progress has been made since then in the country, especially in the field of rare diseases, cancer, precision medicine, and lately public health genomics – a novel discipline that combines genomics and public health. At the European level, Belgium has been involved in three consecutive initiatives, starting with the 1+ Million Genomes Initiative (1+MG) that was launched in 2018 to create a European data infrastructure for genomic data. Two years after the launch, the Beyond 1 Million Genomes (B1MG) project was kicked off in 2020, with the aim of building a federated network of genomic data in Europe. Lastly, in 2022, the Genomic Data Infrastructure (GDI) project began, building on the preparatory work of the 1+MG initiative and the B1MG project (Fig. 1). B1MG developed a framework to enable all interested European countries, including Belgium, to self-evaluate the level of maturity of their national genomic medicine practices following a common matrix, called Maturity Level Model (MLM). GDI aims to capitalise on the experience of B1MG piloting countries and their MLM results. In this paper, we present the qualitative and quantitative outcomes of B1MG MLM assessment in Belgium and discuss their relevance to GDI.