X-Linked Severe Combined Immunodeficiency (X-SCID) is a rare genetic disorder that affects the immune system, making individuals highly susceptible to infections. It is caused by mutations in the IL2RG gene located on the X chromosome, which is crucial for the development of immune cells. As a result, affected individuals often experience severe and recurrent infections from a young age. This condition primarily affects males, as they have only one X chromosome. Treatment options include bone marrow transplantation and gene therapy, which can help restore immune function. Early diagnosis and intervention are essential for improving outcomes and quality of life for those affected.