Evolutionary Restructuring and Systematic Review of the NBPF Gene Family: Comparative Genomics, Functional Divergence, and Disease-Linked Pathways

The Neuroblastoma Breakpoint Family (NBPF) consists of 23 genes, 9 of which are pseudogenes, and is characterized by extensive duplication events and species-specific diversification in Homo sapiens, as well as by the presence of a unique protein domain known as Olduvai (also referred to as DUF1220 or the NBPF domain). Previous studies have attempted to define subfamilies based on the presence of HLS triplet domains; however, this classification has become increasingly unclear with the identification of additional NBPF members. The family remains poorly understood, and the functions of many genes are still unknown, although several have been hypothesized to play key roles in cell proliferation and developmental processes, particularly in neural and skeletal tissues. In this study, we systematically analyzed all available data on the NBPF gene family using the PRISMA-S methodology to infer the biological functions in which these genes may be involved. We also generated multiple phylogenetic trees to support the creation of coherent subfamilies and to correlate the origin of each subfamily with homologous genes in our last common ancestor with the Pan genus, providing what we believe to be one of the most comprehensive phylogenetic reconstructions including all currently annotated NBPF members. Through comparative genomic and phylogenetic analyses, we propose that the NBPF may have originated from a duplication of the PDE4DIP gene, with NBPF26 representing the ancestral member from which the remaining NBPF genes diverged via lineage-specific segmental duplications. In this systematic review and comparative genomic study, we present the first integrative synthesis of our knowledge of the NBPF, encompassing its evolutionary origins, structural dynamics, expression across tissues, and clinical associations.