Targeted high-throughput sequencing for genetic diagnostics of hemophagocytic lymphohistiocytosis

Background: Hemophagocytic lymphohistiocytosis (HLH) is a rapid-onset, potentially fatal hyperinflammatory syndrome. A prompt molecular diagnosis is crucial for appropriate clinical management. Here, we validated and prospectively evaluated a targeted high-throughput sequencing approach for HLH diagnostics. Methods: A high-throughput sequencing strategy of 12 genes linked to HLH was validated in 13 patients with previously identified HLH-associated mutations and prospectively evaluated in 58 HLH patients. Moreover, 2504 healthy individuals from the 1000 Genomes project were analyzed in silico for variants in the same genes. Results: Analyses revealed a mutation detection sensitivity of 97.3 %, an average coverage per gene of 98.0 %, and adequate coverage over 98.6 % of sites previously reported as mutated in these genes. In the prospective cohort, we achieved a diagnosis in 22 out of 58 patients (38 %). Genetically undiagnosed HLH patients had a later age at onset and manifested higher frequencies of known secondary HLH triggers. Rare, putatively pathogenic monoallelic variants were identified in nine patients. However, such monoallelic variants were not enriched compared with healthy individuals. Conclusions: We have established a comprehensive high-throughput platform for genetic screening of patients with HLH. Almost all cases with reduced natural killer cell function received a diagnosis, but the majority of the prospective cases remain genetically unexplained, highlighting genetic heterogeneity and environmental impact within HLH. Moreover, in silico analyses of the genetic variation affecting HLH-related genes in the general population suggest caution with respect to interpreting causality between monoallelic mutations and HLH. A complete understanding of the genetic susceptibility to HLH thus requires further in-depth investigations, including genome sequencing and detailed immunological characterization.Peer reviewe

herg1b Expression as a Potential Specific Marker in Pediatric Acute Myeloid Leukemia Patients with HERG 897K/K Genotype

WOS: 000352806900002PubMed ID: 25247487Human ether-a-go-go related gene (herg) encoding HERG K+ channel has been demonstrated in many previous studies with its association to cell cycle progression and growth in tumor cells. The upregulated expression of HERG K+ channels was determined in different tumor types. Furthermore, not only full-length transcript herg1 but also a truncated isoform herg1b was shown to be expressed in cancer cells. In this study, the expression levels of herg1 and herg1b and the impact of K897T mutation on their expressions were investigated in pediatric acute myeloid leukemia (pAML). Expression levels of herg1 and herg1b isoforms were analyzed by quantitative real time polymerase chain reaction (PCR) in pAML patients together with healthy donors, and their expressions were confirmed by western blotting. The 2690 A>C nucleotide variation in KCNH2 gene corresponding to K897T amino acid change was analyzed by PCR followed by restriction enzyme digestion. herg1b overexpression was observed in tumor cells compared to healthy controls (P = .0024). However, herg1 expression was higher in healthy control cells than tumor cells (P = .001). The prevalence of polymorphic allele 897T was 26% in our patient group and 897T carriers showed increased herg1b expression compared to wild-type allele carriers. Our results demonstrate the presence of the increased levels of herg1b expression in pAML. In addition, we report for the first time that, pAML subgroup with HERG 897K/K genotype compared to 897K/T and T/T genotypes express increased levels of herg1b. In conclusion, HERG 897K/K genotype with increased level of herg1b expression might well be a prognostic marker for pAML.Turkish Hematology Society; Istanbul University Scientific Research ProjectsThe authors thank all the patients and their parents. The authors also thank Turkish Hematology Society and Istanbul University Scientific Research Projects for funding support. The authors wish to extend their thanks to Professor Makbule Aydin of DETAE of Istanbul University for her kind support and Professor Nurhan Ince, of the Biostatistics Department of the School of Medicine of Istanbul University, for advising on statistical issues

How to Manage an Unresectable or Recurrent Sialoblastoma

Only 2-5% of all salivary gland tumors occur in children. Sialoblastoma is an extremely rare salivary gland tumor diagnosed at birth or shortly thereafter with significant variability in histological range and clinical course, so that it may be difficult to predict the most appropriate therapy. In cases where surgical removal is not curative or technically feasible, chemotherapy may be attempted. We report herein a patient with progression of a huge partially resected sialoblastoma who was successfully treated with chemotherapy. Systemic chemotherapy with vincristine, actinomycin D, and cyclophosphamide (VAC) seems to be an effective adjuvant or neoadjuvant treatment option for unresectable or recurrent sialoblastoma. Pediatr Blood Cancer 2010;55:374-376. (C) 2010 Wiley-Liss, Inc

Infantile Hemangiomas: Complications and follow-up

To study the risk factors for hemangioma-related complications, treatment indications and analyze the outcome of patients with infantile hemangioma

Targeted high-throughput sequencing for genetic diagnostics of hemophagocytic lymphohistiocytosis

Background: Hemophagocytic lymphohistiocytosis (HLH) is a rapid-onset, potentially fatal hyperinflammatory syndrome. A prompt molecular diagnosis is crucial for appropriate clinical management. Here, we validated and prospectively evaluated a targeted high-throughput sequencing approach for HLH diagnostics

Targeted high-throughput sequencing for genetic diagnostics of hemophagocytic lymphohistiocytosis

Background: Hemophagocytic lymphohistiocytosis (HLH) is a rapid-onset, potentially fatal hyperinflammatory syndrome. A prompt molecular diagnosis is crucial for appropriate clinical management. Here, we validated and prospectively evaluated a targeted high-throughput sequencing approach for HLH diagnostics. Methods: A high-throughput sequencing strategy of 12 genes linked to HLH was validated in 13 patients with previously identified HLH-associated mutations and prospectively evaluated in 58 HLH patients. Moreover, 2504 healthy individuals from the 1000 Genomes project were analyzed in silico for variants in the same genes. Results: Analyses revealed a mutation detection sensitivity of 97.3 \%, an average coverage per gene of 98.0 \%, and adequate coverage over 98.6 \% of sites previously reported as mutated in these genes. In the prospective cohort, we achieved a diagnosis in 22 out of 58 patients (38 \%). Genetically undiagnosed HLH patients had a later age at onset and manifested higher frequencies of known secondary HLH triggers. Rare, putatively pathogenic monoallelic variants were identified in nine patients. However, such monoallelic variants were not enriched compared with healthy individuals. Conclusions: We have established a comprehensive high-throughput platform for genetic screening of patients with HLH. Almost all cases with reduced natural killer cell function received a diagnosis, but the majority of the prospective cases remain genetically unexplained, highlighting genetic heterogeneity and environmental impact within HLH. Moreover, in silico analyses of the genetic variation affecting HLH-related genes in the general population suggest caution with respect to interpreting causality between monoallelic mutations and HLH. A complete understanding of the genetic susceptibility to HLH thus requires further in-depth investigations, including genome sequencing and detailed immunological characterization