NSD1 is a gene located on chromosome 5 that plays a crucial role in human development. It encodes a protein involved in regulating gene expression, particularly during the early stages of embryonic development. Mutations in this gene can lead to various developmental disorders. The NSD1 protein is part of a larger family of proteins known as histone methyltransferases, which modify histones to influence how DNA is packaged and accessed in cells. Abnormalities in NSD1 function can disrupt normal cellular processes, contributing to conditions such as Sotos syndrome, characterized by overgrowth and cognitive challenges.