A Case of Female X-linked Chronic Granulomatous Disease Caused by X Chromosome Inactivation Treated with Hematopoietic Stem Cell Transplantation and Literature Review.

Objective: X-linked chronic granulomatous disease (X-CGD) is a rare primary immunodeficiency disease characterized by phagocyte dysfunction. It is caused by genetic mutations in the CYBB gene, predominantly affecting males. However, a small number of female carriers can also present with the disease due to biased X chromosome inactivation.1 This study aims to enhance the understanding of X-CGD in a rare case of an infant and young woman and provide insights into its diagnosis and treatment.

Methodology: This study utilized various methods to investigate X-CGD in children and their parents. These methods included assessing neutrophil respiratory burst function, measuring gp91phox protein expression, analyzing chronic granuloma enzyme levels, conducting whole exon gene analysis, and evaluating X chromosome inactivation. Additionally, hematopoietic stem cell transplantation was performed using haploidentical donors from immediate family members.

Results: The children in this study were found to be carriers of the CYBB gene mutation, and their neutrophil respiratory burst function was abnormal with no expression of the gp91phox protein. X chromosome inactivation analysis revealed a rate of 99.5%. Following hematopoietic stem cell transplantation, there was successful engraftment of granulocytes and megakaryocytes, with normalization of gene and enzyme examinations.

Conclusion: The findings of this study highlight the importance of considering X-CGD in the diagnosis of children and women presenting with granulomatous disease. Furthermore, the use of hematopoietic stem cell transplantation was shown to achieve significant therapeutic effects in the treatment of X-CGD. Further research is warranted to explore early diagnostic strategies for X-CGD and to optimize the use of hematopoietic stem cell transplantation in managing the disease. Early diagnosis and intervention can lead to improved outcomes for patients with X-CGD. This study contributes to the understanding of X-CGD and its treatment by demonstrating the possibility of X-CGD in female carriers and the efficacy of hematopoietic stem cell transplantation. These findings emphasize the importance of early diagnosis and highlight the potential for successful outcomes in the management of X-CGD.