Patent protection has been chosen as a strategy to protect new developments in molecular biology such as novel genes and proteins. A way to ensure the protection of genetic inventions is to claim a set of sequences that are associated with the described genetic sequences in terms of structure and/or biological activity, in a genus claim. Clearly, achieving an effective patent protection for proteins and genetic sequences is a real challenge for an Intellectual Property manager, considering the unpredictability of biological sciences and the diversity in current patent law and patent office guidance in each territory. This paper seeks to study the Brazilian patent office procedures about genus claims for biological sequences while comparing them with two other national/regional offices. To achieve this result, we initially present the concepts, followed by the current requirements and the barriers to obtain genus claims for biological sequences in the legal framework and patent office prosecution of Brazil, the European Union, and the United States. Subsequently, we study the impacts of these regulations in the scope of claim protection in each territory. This is done by comparing patent documents with the same priority granted in each of these offices in order to analyze the extension of the owner’s rights for biological sequences. Understanding the logic that supports the examination procedures in the three studied offices will be important to subsidize the legal protection for gene-based inventions. Therefore, this would support the development of a patent system that can provide satisfactory safeguard for the results of investments in biotechnology Research and Development initiatives.2021-12-31