Secondary Hemophagocytic Syndrome Associated with COG6 Gene Defect: Report and Review.

Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal disease that is characterized by proliferation and infiltration of hyperactivated macrophages and T-lymphocytes. Clinically, it is characterized by prolonged fever, hepatosplenomegaly, hypertriglyceridemia, hypofibrinogenemia, pancytopenia, and hemophagocytosis in the bone marrow, spleen, or lymph nodes. It can be classified as primary if it is due to a genetic defect, or secondary if it is due to a different etiology such as severe infection, immune deficiency syndrome, rheumatological disorder, malignancy, and inborn errors of metabolism such as galactosemia, multiple sulfatase deficiency, lysinuric protein intolerance, Gaucher disease, Niemann-Pick disease, Wolman disease, propionic acidemia, methylmalonic acidemia, biotinidase deficiency, cobalamin C defect, galactosialidosis, Pearson syndrome, and long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency. For the first time in the literature, we report on a 5-year-old girl diagnosed with a Component of Oligomeric Golgi Complex 6 (COG6) gene defect complicated by HLH. Finally, we review the literature on inborn errors of metabolism associated with HLH and compare the previously reported patients of COG6 gene defect with our patient.