Diagnostic test assessment. Validation study of an alternative system to detect microsatellite instability in colorectal carcinoma.

The American Society for Clinical Pathology (ASCP), College of American Pathologists (CAP), Association for Molecular Pathology (AMP), and the American Society of Clinical Oncology (ASCO) have been recently strongly recommended the evaluation of mismatch repair status (MMS) as molecular biomarkers in colorectal cancer for a better prognostic stratification of patients. This recommendation is emphasized by the recent evidence of Microsatellite Instability (MSI) as a predictive marker for chemotherapy and immunotherapy.In this scenario, the validation of molecular biomarker testing methods seems to be essential to design the most appropriate tailored therapy and the most suitable care strategy, respectively.In this study, we validated an alternative method based on capillary electrophoresis system label-free PCR (Qiaxcel system) to evaluate the MSI Bethesda Panel. We also parallel the results with a standard approach.Our data showed total concordance with the standard approach, with a highly time-efficient and easy procedure combined with high sensitivity for MSI detection.Alternative capillary electrophoresis based on label-free PCR such as the Qiaxel system is a very sensitive and specific method to detect MSI for the management of patients with colorectal cancer. This procedure is adequate and suitable in diagnostic routine for the evaluation of microsatellite repeats compared to standard procedures.

The spectrum of non-classical Diamond-Blackfan anemia: a case of late beginning transfusion dependency associated to a new RPL5 mutation.

Diamond Blackfan anemia typically presents in infants and is often associated with many kinds of malformations. Severity of anemia often needs transfusional support in the first months of life. We describe here a patient with Diamond Blackfan anemia related to a RPL5 mutation. The patient had no physical abnormalities and experienced a very late onset of transfusion dependency.

Vocal cord palsy after vincristine treatment in a child and the inefficacy of glutamic acid in the prevention of relapse: a case report.

INTRODUCTION: Vincristine is an antineoplastic drug with a well known efficacy for the treatment of acute lymphoblastic leukemia and many solid tumors. No more than 20 pediatric patients with vincristine-induced vocal cord palsy have been reported, and to the best of our knowledge this is the first case where glutamic acid was administered with the aim of preventing a relapse of laryngeal dysfunction. CASE PRESENTATION: The larynx paralysis presented with hoarseness and stridor in a Caucasian 18-month-old girl and spontaneously resolved in about a month. In order to administer a subsequent full dose of vincristine, our patient received oral glutamic acid whose efficacy against vincristine neurological side effects has been previously reported. CONCLUSIONS: Since in our patient the amino acid proved to be ineffective in the prevention of laryngeal paralysis relapse, we suggest that a dose reduction of vincristine should be preferred by oncologists as an initial approach after a case of drug-induced vocal cord palsy.

Mutations affecting mRNA splicing are the most common molecular defect in patients with familial hemophagocytic lymphohistiocytosis type 3.

Mutations of UNC13D have been described in patients affected by familial hemophagocytic lymphohistiocytosis (FHL3). The Munc13-4 protein contributes to the priming of the secretory granules. Mutation in this gene results in defective cellular cytotoxicity and the familial hemophagocytic lymphohistiocytosis clinical picture. Among reported mutations, few are predicted to impair splicing. Yet, functional impact of these mutations has not been addressed. We identified 18 out of 31 familial hemophagocytic lymphohistiocytosis families showing at least one mutation responsible for splicing error. We identified some known and three novel splicing mutations: one falls at the acceptor site of exon 11 and 2 are deep intronic mutations in IVS1 and in IVS30. We demonstrated that these deep intronic mutations affect regulatory sequences causing aberrant splicing. We report that UNC13D mutations leading to splicing errors represent the majority of mutations observed in familial hemophagocytic lymphohistiocytosis. This finding has implications for designing strategies for analysis of the families with suspected familial hemophagocytic lymphohistiocytosis.

Germline mutations of the perforin gene are a frequent occurrence in childhood anaplastic large cell lymphoma.

BACKGROUND: Monoallelic and biallelic mutations of the PRF1 gene have been reported in some cases of childhood lymphoma. Anaplastic large cell lymphoma (ALCL) accounts for 10% to 15% of all childhood lymphomas. To assess the possible role of PRF1 mutations in ALCL, the authors screened a series of patients collected by the Associazione Italiana di Ematologia Oncologia Pediatrica (AIEOP). METHODS: The authors investigated 44 patients with ALCL by direct sequence of the PRF1 gene. To address the issue of the prevalence of the most frequently observed PRF1 mutations in the control population, the authors examined a series of 400 healthy white control subjects for the 272C>T mutation (A91V). RESULTS: A total of 6 different mutations were identified in 12 patients (27.3%). Eleven patients had 1 mutation whereas 1 patient was found to have 2 mutations. Of the 6 PRF1 mutations identified, 2 were novel mutations: 529C>T (resulting in R177C) and 1471G>A (resulting in D491N). The remaining 4 mutations were previously described; in particular, the 272C>T mutation (resulting in the A91V amino acid change) was found in 8 patients, whereas the 368G>A (R123H), 695G>A (R232H), and 1262T>G (F421C) mutations were all found in 1 case each. Overall, the incidence of PRF1 mutations was found to be significantly higher in patients with ALCL compared with 400 control subjects, among whom only heterozygous A91V was observed in 41 subjects (10.2%) (chi-square test, 10.9; P <.01). CONCLUSIONS: Patients with childhood ALCL have a higher probability of being a carrier of a PRF1 mutation compared with healthy controls, suggesting a possible predisposing role.

A single amino acid change A91V in perforin: a novel, frequent predisposing factor to childhood acute lymphoblastic leukemia?

We screened 100 children with acute lymphoblastic leukemia (ALL) to assess the incidence of single amino acid change A91V in perforin. Heterozygous A91V was found in 12/100 patients and 5/127 controls (OR, 3.4; 95%CI: 1.15-9.95; p=0.014). A91V is a novel and frequent predisposing factor for childhood ALL.