[Recurrent thrombocytopenia with hemolytic anemia in a boy aged 3 years].

A boy, aged 3 years and 8 months, had recurrent thrombocytopenia with hemolytic anemia for more than 3 years. The physical examination showed no enlargement of the liver, spleen, and lymph nodes or finger deformities. Laboratory results showed a negative result of the direct antiglobulin test, normal coagulation function, and increases in bilirubin, lactate dehydrogenase and reticulocytes. The results of von Willebrand factor-cleaving protease ADAMTS13 activity assay showed extreme deficiency, and antibody assay showed negative ADAMTS13 inhibitory autoantibodies. Next-generation sequence showed compound heterozygous mutation in the ADAMTS13 gene. The boy was diagnosed with congenital thrombotic thrombocytopenic purpura. This disease may be easily misdiagnosed as Evans syndrome and is difficult to diagnose in clinical practice. The child had developed the disease since birth, but it took 3 years to make a confirmed diagnosis. Therefore, congenital thrombotic thrombocytopenic purpura should be considered for children with jaundice at birth, recurrent thrombocytopenia with hemolytic anemia, and negative results of the direct antiglobulin test. The detection of ADAMTS13 activity and ADAMTS13 inhibitory autoantibodies should be performed as soon as possible for a definite diagnosis, and gene detection should be performed to make a confirmed diagnosis when necessary.

[Clinical effect of multicenter multidisciplinary treatment in children with renal malignant tumors].

OBJECTIVE: To study the long-term clinical effect of multicenter multidisciplinary treatment (MDT) in children with renal malignant tumors. METHODS: A retrospective analysis was performed on the medical data of 55 children with renal malignant tumors who were diagnosed and treated with MDT in 3 hospitals in Hunan Province from January 2015 to January 2020, with GD-WT-2010 and CCCG-WT-2016 for treatment regimens. A Kaplan-Meier survival analysis was used to analyze the survival of the children. RESULTS: Of the 55 children, 10 had stage I tumor, 14 had stage Ⅱ tumor, 22 had stage Ⅲ tumor, 7 had stage IV tumor, and 2 had stage V tumor. As for pathological type, 47 had FH type and 8 had UFH type. All children underwent complete tumor resection. Of the 55 children, 14 (25%) received preoperative chemotherapy. All children, except 1 child with renal cell carcinoma, received postoperative chemotherapy. Among the 31 children with indication for radiotherapy, 21 (68%) received postoperative radiotherapy. One child died of postoperative metastasis. The incidence rate of FH-type myelosuppression was 94.4%, and the incidence rate of UFH-type myelosuppression was 100%. The median follow-up time was 21 months and the median survival time was 26 months for all children, with an overall survival rate of 98% and an event-free survival rate of 95%. CONCLUSIONS: Multicenter MDT has the advantages of high success rate of operation and good therapeutic effect of chemotherapy in the treatment of children with renal malignant tumors, with myelosuppression as the most common side effects, and radiotherapy is safe and effective with few adverse events. Therefore, MDT has good feasibility, safety, and economy.

[Clinical and genetic analyses of juvenile myelomonocytic leukemia].

OBJECTIVE: To study the clinical and genetic features of juvenile myelomonocytic leukemia (JMML) and the association between genotype and prognosis. Methods The clinical data of 15 children who were diagnosed with JMML were collected. Next-generation sequencing was used to detect common gene mutations of JMML. RESULTS: The male/female ratio was 6.5:1, and the age of onset was 19 months (range 2-67 months). Of the 15 children, 11 (73%) experienced disease onset before the age of 4 years, with abdominal distension and pyrexia as initial symptoms. All children had hepatosplenomegaly and superficial lymphadenectasis, with a number of peripheral blood mononuclear cells of >1.0×109/L and a percentage of juvenile cells of 1%-7% in peripheral blood smear. The percentage of bone marrow blasts + juvenile cells was <20%, and the percentage of monoblasts + promonocytes was 1%-10%. Of the 15 children, 10 (67%) had a higher level of hemoglobin F than the normal level at the corresponding age, with the highest level of 62.5%. All 15 children had the absence of Philadelphia chromosome, and one child had chromosome 7 deletion. All 15 children had a negative result of BCR/ABL fusion gene detection. PTPN11 gene mutation was found in 5 children (33%), NF1 mutation in 4 children (27%), CBL mutation in 3 children (20%), and RAS mutation in 3 children (20%). No children received regular chemotherapy, and one child underwent hematopoietic stem cell transplantation. The median follow-up time of 15 children was 18 months (range 1-48 months). Among the 15 children, 8 died (among whom 4 had PTPN11 gene mutation, 3 had NF1 mutation, and 1 had RAS mutation) and 7 survived. The children with PTPN11 mutation had the worst prognosis and the highest mortality rate, and those with CBL or NRAS mutation had a relatively good prognosis. The level of hemoglobin F was negatively correlated with survival time (rs=-7.21, P=0.002). CONCLUSIONS: In children with JMML, the type of gene mutation is associated with prognosis. The children with PTPN11 mutation often have a poor prognosis, and those with CBL or NRAS mutation have a relatively good prognosis.

[Application of enzyme assay and gene analysis in the prenatal diagnosis for a family with glycogen storage disease type II].

OBJECTIVE: To carry out prenatal diagnosis for a glycogen storage disease type II (GSD II ) affected family. METHODS: The acid-α -glucosidase (GAA) activity was measured in whole leukocytes and cultured amniocytes with 4-methylumbelliferyl-α -D-glucopyranoside as substrate and with acarbose as inhibitor. The coding regions of GAA gene were amplified by polymerase chain reaction and analyzed by direct DNA sequencing. RESULTS: The proband and the fetus had low GAA activity (12.3% and 1.1% of the average normal range, respectively). Mutation analysis of the GAA gene revealed a novel nonsense mutation p.W738X and a reported nonsense mutation p.E888X in both the proband and the fetus; the reported pseudodeficiency allele c.[1726G to A: 2065G to A] was found in the proband, the mother and the fetus. CONCLUSION: The proband and the fetus were both GSD II affected. A combination of GAA activity analysis and mutation analysis is efficient for the prenatal diagnosis of GSD II. Mutation analysis should be a routine method in the prenatal diagnosis of GSD II in Asian population, where pseudodeficiency allele can cause low GAA activity in normal individuals which is relatively common in Asian.