[Ras-associated autoimmune leukoproliferative disorder: a report of 2 cases and literature review]

Objective: To investigate the clinical features and genetic characteristics of cases with Ras-associated autoimmune leukoproliferative disorder(RALD). Method: Characteristics of clinical data and gene mutation of the first two cases in China with RALD were retrospectively analyzed. The related literature was searched by using search terms "NRAS" , "KRAS" or "RALD" . Result: Case1, a seven-year-seven-month old girl, was admitted due to "thrombocytopenia and splenomegaly for three years" . Palpation showed enlargement of submandibular lymph nodes and hepatosplenomegaly.The platelet count fluctuated between 15×10(9)/L and 60×10(9)/L. Hemoglobin was as 57 g/L and Coomb's test was positive.Lung computed tomography revealed interstitial lung disease, bilateral pleural effusion, pericardial effusion, myocardial injury and ascites. Case2, a seven-year-five-month old girl, was admitted due to "recurrent thrombocytopenia for seven years, intermittent eyelid and abdominal swelling for three years" . Palpation showed enlargement of cervical and right inguinal lymph nodes, and hepatosplenomegaly.The number of platelet and monocyte were 9×10(9)/L and 5.46×10(9)/L, respectively. Bone marrow smear revealed an increase in the proportion of primitive immature cells (0.09 to 0.11). Lung computed tomography revealed interstitial lung disease, pericardial effusion, cardiac enlargement and pulmonary hypertension. The gene sequencing results showed KRAS gene c.38G> A somatic mutation in case1, and p.G12D and NRAS gene c.38G> A, p.G13D somatic mutation in case2. A total of 8 reports were retrieved including 23 cases caused by NRAS(10 cases) or KRAS(13 cases) gene somatic mutation. All the 23 cases showed hypergammaglobulinemia, splenomegaly, B cells hyperplasia or mononucleosis. Conclusion: RALD often manifests as hepatosplenomegaly,lymphoproliferation, autoimmune hematocytopenia, B cells hyperplasia or mononucleosis, hypergammaglobulinemia. Gene sequencing analysis can help diagnose the disease.