This study aims to collect peripheral blood samples from children with Williams syndrome (WS) and healthy children, establish a cell line of induced pluripotent stem cells (iPSCs) derived from the subjects, and further induce and differentiate them into neural progenitor cells (NPCs) and oligodendrocyte lineage cells for in vitro studies on the cellular and molecular mechanisms of WS-related neurodevelopmental abnormalities. Based on previous basic and pre-experimental results, the study focuses on the developmental transition of oligodendrocyte lineage from OPC to pre-OL, immature oligodendrocytes, and mature oligodendrocytes, and specifically evaluates the programs of myelin-related genes, differentiation trajectories, and abnormalities in related pathways such as GTF2I/FZD9, ERK/MAPK, and Wnt/β-catenin. The study design is an independent donor case-control study, and it plans to include 3 children with WS and 3 healthy children. Each sample will be independently sequenced.