Polyamines are ubiquitous in almost all biological entities and involved in various crucial physiological processes. They are also closely associated with the onset and progression of many diseases. Polyaminopathies are a group of rare genetic disorders caused by alterations in the function of proteins within the polyamine metabolism network. Although the identified polyaminopathies are all rare diseases at present, they are genetically heritable, rendering high risks not only to the carriers but also to their descendants. Meanwhile, more polyaminopathic patients might be discovered with the increasing accessibility of gene sequencing. This review aims to provide a comprehensive overview of the structural variations of mutated proteins in current polyaminopathies, in addition to their causative genes, types of mutations, clinical symptoms, and therapeutic approaches. We focus on analyzing how alterations in protein structure lead to protein dysfunction, thereby facilitating the onset of diseases. We hope this review will offer valuable insights and references for the future clinical diagnosis and precision treatment of polyaminopathies.