Assessing the efficacy of target adaptive sampling long-read sequencing through hereditary cancer patient genomes.

Innovations in sequencing technology have led to the discovery of novel mutations that cause inherited diseases. However, many patients with suspected genetic diseases remain undiagnosed. Long-read sequencing technologies are expected to significantly improve the diagnostic rate by overcoming the limitations of short-read sequencing. In addition, Oxford Nanopore Technologies (ONT) offers adaptive sampling and computationally driven target enrichment technology. This enables more affordable intensive analysis of target gene regions compared to standard non-selective long-read sequencing. In this study, we developed an efficient computational workflow for target adaptive sampling long-read sequencing (TAS-LRS) and evaluated it through application to 33 genomes collected from suspected hereditary cancer patients. Our workflow can identify single nucleotide variants with nearly the same accuracy as the short-read platform and elucidate complex forms of structural variations. We also newly identified several SINE-R/VNTR/Alu (SVA) elements affecting the APC gene in two patients with familial adenomatous polyposis, as well as their sites of origin. In addition, we demonstrated that off-target reads from adaptive sampling, which is typically discarded, can be effectively used to accurately genotype common single-nucleotide polymorphisms (SNPs) across the entire genome, enabling the calculation of a polygenic risk score. Furthermore, we identified allele-specific MLH1 promoter hypermethylation in a Lynch syndrome patient. In summary, our workflow with TAS-LRS can simultaneously capture monogenic risk variants including complex structural variations, polygenic background as well as epigenetic alterations, and will be an efficient platform for genetic disease research and diagnosis.

Prognostic impact of the multimodal treatment approach in patients with C19MC-altered embryonal tumor with multilayered rosettes.

OBJECTIVE: Embryonal tumor with multilayered rosettes (ETMR) is one of the childhood central nervous system tumors with the poorest prognosis; thus, establishing an optimal treatment strategy is essential, However, because of the low incidence and molecular heterogeneity of the tumor, the optimal treatment has not yet been determined. In this study the authors evaluated the prognostic impact of a multimodal treatment approach in patients with ETMR. METHODS: The authors evaluated 4 patients with ETMR at their institution who showed varied clinical features and also conducted clinical characterization and prognostic analysis of previously reported cases of the ETMR-presenting locus 19q13.42 with a chromosome 19 microRNA cluster (C19MC) amplification, which is known to be a diagnostic hallmark of the tumor. RESULTS: Of the 4 patients with ETMR in the authors' institution, in 1 case the patient's tumor showed a neuroblastoma-like appearance without multilayered rosettes; however, the diagnosis was confirmed by the presence of amplified C19MC. From a clinical standpoint, 2 patients who underwent gross-total resection (GTR) of the tumor and chemotherapy followed by high-dose chemotherapy (HDC) had long-term complete remission with or without local irradiation. In the multivariate analysis of 43 cases with C19MC-altered ETMR reported in the literature, HDC and local irradiation were significantly correlated with better event-free survival (HR 0.17, p = 0.0087; HR 0.17, p = 0.010) and overall survival (OS) (HR 0.29, p = 0.023; HR 0.28, p = 0.019), respectively. GTR was also correlated with better OS (HR 0.40, p = 0.039). CONCLUSIONS: This case series demonstrated pathological and clinical heterogeneity among ETMR cases and the diagnostic importance of the molecular genetic approach among embryonal tumors, particularly during infancy. Based on the results of the analysis of molecularly uniformed ETMR cases, multimodal treatment may play a significant role in the prognosis of these tumors.

[Gilteritinib for pediatric FLT3 internal tandem duplication-positive recurrent acute myeloid leukemia].

Gilteritinib is an FMS-like tyrosine kinase 3 (FLT3) inhibitor that has shown efficacy in patients with refractory or recurrent adult acute myeloid leukemia (AML) with FLT3 mutations. However, there are limited data for pediatric patients treated with this drug. Herein, we report the clinical courses of two children with FLT3-mutated recurrent AML who received gilteritinib. Case 1: An 11-year-old boy with secondary relapsed AML presented with an FLT3 internal tandem duplication (ITD) since the first recurrence. One week after gilteritinib initiation, blasts, which had comprised 90% of the white blood cells before treatment, almost disappeared from the peripheral blood without tumor lysis syndrome. The patient developed multiple adverse effects and died from the disease 2.5 months after gilteritinib initiation. Case 2: A 12-year-old girl diagnosed with AML was positive for FLT3 ITD. She received gilteritinib during her first relapse post-stem cell transplantation. After the drug was administered, the recipient cell counts increased, as determined by molecular tests (i.e., FISH), whereas microscopically, there was a complete response for 5 months with good performance status. Gilteritinib treatment in children with FLT3-mutated recurrent AML is feasible and effective. As a patient experienced several adverse effects with gilteritinib treatment, clinical trials are required to determine the appropriate pediatric dose of this medication.

Nonosmotic secretion of arginine vasopressin and salt loss in hyponatremia in Kawasaki disease.

BACKGROUND: The precise mechanism of hyponatremia in Kawasaki disease (KD) remains elusive because assessment of volume status based on serial changes in body weight is lacking in previous reports. METHODS: Seventeen patients who were diagnosed with KD and hyponatremia (serum sodium levels <135 mmol/L) were analyzed. Volume status was assessed based on serial changes in body weight. Plasma arginine vasopressin (ADH), urine electrolytes, and serum cytokine levels were measured on diagnosis of hyponatremia. An increase in body weight by >3% was defined as hypervolemia and a decrease in body weight by >3% was defined as hypovolemia. RESULTS: The volume status was hypervolemic in three patients (18%), euvolemic in 14 (82%), and hypovolemic in none (0%). Five (29%) patients were diagnosed with "syndrome of inappropriate secretion of antidiuretic hormone" (SIADH) and no patients were diagnosed with hypotonic dehydration. The contribution of decreased total exchangeable cations (salt loss) to hyponatremia (5.9% [interquartile range, 4.3%, 6.7%]) was significantly larger than that of increased total body water (-0.7% [-1.8%, 3.1%]) (P = 0.004). Serum interleukin-6 levels were elevated in all of the nine patients who were evaluated. Among the 12 (71%) patients who did not meet the criteria of SIADH and hypotonic dehydration, plasma ADH levels were inappropriately high in ten patients. These patients were also characterized by euvolemic or hypervolemic hyponatremia and salt loss, which might be compatible with a diagnosis of SIADH. CONCLUSIONS: Our study shows that hyponatremia in KD is euvolemic or hypervolemic and is associated with nonosmotic secretion of ADH and salt loss in the majority of patients.

A case of primary cardiac lymphoma located in the pericardial effusion.

Primary cardiac lymphoma is a rare disorder with a poor prognosis. We present here a case of 77-year-old woman who was diagnosed as having cardiac lymphoma antemortem according to a cytologic examination of the pericardial effusion. Determination of the levels of serum-soluble interleukin-2 receptor and serum deoxythymidine kinase was useful for the diagnosis. Echocardiography, computed tomography, magnetic resonance imaging, and gallium scan revealed neither lymphadenopathy nor tumor in the heart, so she was diagnosed as having malignant lymphoma that probably originated from the pericardium. Systemic chemotherapy with CHOP (cyclophosphamide, farmorubicin, oncovin, and prednisolone) resulted in a complete resolution of the pericardial effusion. She has been in remission 48 months after discontinuation of the chemotherapy.

An autopsy case of gallbladder cancer developing in a Japanese man with cerebrotendinous xanthomatosis: genetic analysis of the sterol 27-hydroxylase and p53 genes.

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid-storage disorder characterised by xanthomas, neurological dysfunctions and premature atherosclerosis. A case of a well differentiated adenocarcinoma of the gallbladder occurring in a 57-year-old Japanese man with CTX, confirmed clinically, biochemically and at autopsy is reported together with analyses of the sterol 27-hydroxylase (CYP27) and p53 genes. A missense mutation of the p53 (G for C) was detected in the gallbladder adenocarcinoma. Direct sequence analysis also showed a silent mutational substitution of unknown significance, C for A, in CYP27 at codon 89. In the past, CTX patients have only demonstrated this infrequently, indicating no direct relationship between CYP27 dysfunction and tumour development. Thus, the present case of gallbladder cancer appears to be a chance occurrence.