Lamins are essential for maintaining the mechanical stability of the nucleus and organizing chromatin. B-type lamins are expressed early in embryogenesis, particularly in the central nervous system, where they are crucial for development. In contrast, A-type lamins are predominantly expressed in differentiated cells and are vital for maintaining nuclear stability and chromatin organization. These differences likely account for the distinct clinical characteristics of B-type and A-type laminopathies: B-type laminopathies primarily affect the central nervous system, whereas A-type laminopathies are mainly associated with metabolic dysfunction, cardiopathies, and premature aging. In this chapter, we explore the broad and heterogeneous group of diseases caused by lamin alterations, detailing the genetic basis of laminopathies, their clinical manifestations, and the current state of research. We also discuss clinical management strategies and the role of chromatin organization in the pathophysiology of these diseases. Finally, we examine the variations in A- and B-type lamin expression in cancer.