A self-repair history: compensatory effect of a de novo variant on the FANCA c.2778+83C>G splicing mutation.

Introduction: Fanconi anemia (FA) is a genome instability condition that drives somatic mosaicism in up to 25% of all patients, a phenomenon now acknowledged as a good prognostic factor. Herein, we describe the case of P1, a FA proband carrying a splicing variant, molecularly compensated by a de novo insertion. Methods and Results: Targeted next-generation sequencing on P1's peripheral blood DNA detected the known FANCA c.2778 + 83C > G intronic mutation and suggested the presence of a large deletion on the other allele, which was then assessed by MLPA and RT-PCR. To determine the c.2778 + 83C > G splicing effect, we performed a RT-PCR on P1's lymphoblastoid cell line (LCL) and on the LCL of another patient (P2) carrying the same variant. Although we confirmed the expected alternative spliced form with a partial intronic retention in P2, we detected no aberrant products in P1's sample. Sequencing of P1's LCL DNA allowed identification of the de novo c.2778 + 86insT variant, predicted to compensate 2778 + 83C > G impact. Albeit not found in P1's bone marrow (BM) DNA, c.2778 + 86insT was detected in a second P1's LCL established afterward, suggesting its occurrence at a low level in vivo. Minigene assay recapitulated the c.2778 + 83C > G effect on splicing and the compensatory role of c.2778 + 86insT in re-establishing the physiological mechanism. Accordingly, P1's LCL under mitomycin C selection preserved the FA pathway activity in terms of FANCD2 monoubiquitination and cell survival. Discussion: Our findings prove the role of c.2778 + 86insT as a second-site variant capable of rescuing c.2778 + 83C > G pathogenicity in vitro, which might contribute to a slow hematopoietic deterioration and a mild hematologic evolution.

Primary breast lymphoma of childhood: a case report and review of literature.

BACKGROUND: Primary breast lymphoma (PBL) is an extremely rare neoplasm in children; by definition, it manifests in the breast without evidence of lymphoma elsewhere, except ipsilateral axillary nodes. CASE PRESENTATION: We report a case of a 15-year-old girl diagnosed with diffuse large B-cell lymphoma (DLBCL) of the right breast: the patient received chemotherapy and rituximab, achieving complete remission. A literature review revealed other 11 cases of pediatric PBL; it mainly affects female adolescents and can involve right and left breast equally. Different histologic subtypes have been described, arising from both B-cell and T-cell. Therapeutic approaches were very different, from chemotherapy to local treatment with surgery and/or radiotherapy. CONCLUSIONS: Our case is the first in which rituximab was administered, suggesting to be a promising therapy in B-cell PBL, as already demonstrated in pediatric B-cell lymphoma from other sites. Further investigations are needed to identify prognostic factors and establish the most effective treatment.

Association of Immune Thrombocytopenia and Inflammatory Bowel Disease in Children.

BACKGROUND: The association between inflammatory bowel disease (IBD) and immune thrombocytopenia (ITP) is still uncertain. In this multicenter retrospective study, the coexistence of both diseases was investigated in children diagnosed from 1 January 2000 to 31 December 2019. METHODS: Clinical characteristics of both IBD and ITP, onset of disorders, and patient's response to treatment were collected through a structured form sent to 55 Italian pediatric referring centers for hematological disorders. RESULT: Centers responded to the survey and reported the coexistence of IBD and ITP in 14 children. The first diagnosis was ITP in 57.1% and IBD in 35.7% of patients: it was simultaneous in 7.1%. IBD was classified as ulcerative colitis (57.1%), Crohn disease (35.7%), and unclassified (7.1%). No therapy for IBD other than steroids had any effect on ITP course. Colectomy resulted in recovery from ITP in 1 of the 2 patients surgically treated. ITP was always mild but turned to be chronic in half of patients. CONCLUSIONS: In all patients, ITP was mild without any evident impact on IBD severity, but the incidence of chronic ITP seems to be higher than what is usually observed in the pediatric age group. Colectomy had unpredictable effects on ITP.

Association of Immune Thrombocytopenia and Celiac Disease in Children: A Retrospective Case Control Study

Objective: The association between celiac disease (CD) and immune thrombocytopenia (ITP) is still uncertain. The aim of this study was to characterize the coexistence of these two diseases in Italian children. Materials and Methods: This is a retrospective multicenter study investigating the occurrence of CD in 28 children with ITP diagnosed from January 1, 2000, to December 31, 2019. Results: The first diagnosis was ITP in 57.1% and CD in 32.1% of patients. In 3 patients (10.7%), the two diagnoses were simultaneous. All the potential and silent cases of CD in our cohort were diagnosed in the groups of "ITP first" and "simultaneous diagnosis". In all children ITP was mild, and in 2 out of 8 not recovered from ITP at the time of CD diagnosis a normalization of platelet counts (>100,000/µL) occurred 3 and 5 months after starting a gluten-free diet, respectively. Conclusion: We think that screening for CD should be considered in children with ITP regardless of the presence of gastrointestinal symptoms. Furthermore, some patients may recover from ITP after starting a gluten-free diet.

Rasburicase-induced Methemoglobinemia: A Case Report and Literature Review.

Rasburicase is a recombinant urate oxidase enzyme indicated for tumor lysis syndrome, a potential life-threatening oncologic emergency that occurs most commonly during initial chemotherapy for hematological malignancies. As a result of the defects in the physiological antioxidant pathway, erythrocytes of patients with glucose-6-phosphate dehydrogenase deficiency are not protected against the oxidizing stress exerted by hydrogen peroxide generated with the administration of rasburicase. The authors report a 14-year-old patient, diagnosed with T-cell acute lymphoblastic leukemia, who developed methemoglobinemia and hemolytic anemia with low oxygen saturation after starting steroids, hyperhydratation, and rasburicase administration. The complications resolved with supportive therapy only.

Different Cardiac Anomalies in Mother and Son with 4q-Syndrome.

We report a female patient with asymptomatic cor triatriatum sinister, associated with 4q34.3 deletion. Her child, carrying the same imbalance, suffers from tetralogy of Fallot. To the best of our knowledge, this is the first reported case of cor triatriatum associated with deletion of the long arm of the chromosome 4; furthermore, the majority of patients with chromosome 4 long arm syndrome have de novo deletions and only few familial cases have been reported so far.