Infantile malignant osteopetrosis caused by a new mutation of TCIRG1 gene： a case report

Infantile malignant osteopetrosis （IMO） is mainly manifested with the increased bone density, smaller bone marrow cavity and severe extramedullary hematopoiesis. At present, hematopoietic cell transplantation represents the only curative treatment for IMO. In this article, we reported a 3-month-old male infant with IMO. He was admitted due to abnormal hemograms for 10 d at 9 d after incarcerated right oblique inguinal hernia surgery. Clinical manifestations mainly included inspiratory dyspnea, hepatosplenomegaly and decreased levels of hemoglobin and platelets. Thoracic and pelvic X-ray examination and CT scan of head and neck revealed increased bone density. High-resolution clinical exome sequencing detected homozygous mutation of c. 1480delC （p.Q494Sfs*34） in the T-cell immune regulator 1（TCIRG1） gene, which has not been reported yet. Sequencing data showed that this mutation was inherited from his parents （heterozygous status in his parents, his parents were cousins）.