The outbreak of coronavirus disease 2019 (COVID-19), which began in December 2019, is still ongoing in Korea, with >9,000 confirmed cases as of March 25, 2020. COVID-19 is a severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection, and real-time reverse transcription-PCR is currently the most reliable diagnostic method for COVID-19 around the world. Korean Society for Laboratory Medicine and the Korea Centers for Disease Prevention and Control propose guidelines for diagnosing COVID-19 in clinical laboratories in Korea. These guidelines are based on other related domestic and international guidelines, as well as expert opinions and include the selection of test subjects, selection of specimens, diagnostic methods, interpretation of test results, and biosafety.

Context: Detection of the BRAF V600E mutation in fine-needle aspiration cytology (FNAC) specimens may increase the value of FNAC. Objective: The objectives of the study was to compare the diagnostic performance of BRAF assays that differ in sensitivity and to examine the associations between the BRAF V600E mutation status and the clinicopathological features in papillary thyroid carcinoma (PTC). Design and Setting: Three molecular assays were performed in all subjects and compared with regard to FNAC and histology results. Participants: We evaluated 4585 consecutive patients who were found to have malignant or indeterminate thyroid nodules by ultrasonography. Outcome Measures: All FNAC samples were tested for the BRAF V600E mutation using conventional Sanger sequencing, dual-priming oligonucleotide-PCR, and mutant enrichment with 3′-modified oligonucleotide (MEMO) sequencing. Results: The detection sensitivities of the three molecular assays for the BRAF V600E mutation were 20, 2, and 0.1%, respectively. Compared with conventional Sanger sequencing (n = 673), dual-priming oligonucleotide-PCR and MEMO sequencing detected more tumors with the BRAF V600E mutation (n = 919 and n = 1044, respectively), especially tumors with a benign, indeterminate, or nondiagnostic cytology. All BRAF-positive tumors that were histologically examined were shown to be PTC, regardless of cytology results. The clinical sensitivities of the three assays for detecting PTC were 54.8, 74.4, and 79.7%, respectively. BRAF V600E mutations in microcarcinomas (≤10 mm) were detected more efficiently as the detection sensitivity of the assay increased (P < 0.001). Tumor size correlated significantly with multifocality, extrathyroidal extension, and lymph node metastasis (P = 0.003, P < 0.001 and P < 0.001, respectively), but the BRAF V600E mutation status was not associated with any of those features. Conclusion: Highly sensitive and specific molecular assays such as MEMO sequencing are optimal for detecting the BRAF mutations in thyroid FNAC because these techniques can detect PTC that might be missed by cytology or less sensitive molecular assays.

Objectives: Pathogenic mutations in developmental and epileptic encephalopathy (DEE) are increasingly being discovered. However, little has been known about effective targeted treatments for this rare disorder. Here, we assessed the efficacy of ketogenic diet (KD) according to the genes responsible for DEE. Methods: We retrospectively evaluated the data from 333 patients who underwent a targeted next-generation sequencing panel for DEE, 155 of whom had tried KD. Patients showing ≥90% seizure reduction from baseline were considered responders. The KD efficacy was examined at 3, 6, and 12 months after initiation. Patients were divided into those with an identified pathogenic mutation (n = 73) and those without (n = 82). The KD efficacy in patients with each identified pathogenic mutation was compared with that in patients without identified genetic mutations. Results: The responder rate to KD in the patients with identified pathogenic mutations (n = 73) was 52.1, 49.3, and 43.8% at 3, 6, and 12 months after initiation, respectively. Patients with mutations in SCN1A (n = 18, responder rate = 77.8%, p = 0.001), KCNQ2 (n = 6, responder rate = 83.3%, p = 0.022), STXBP1 (n = 4, responder rate = 100.0%, p = 0.015), and SCN2A (n = 3, responder rate = 100.0%, p = 0.041) showed significantly better responses to KD than patients without identified genetic mutations. Patients with CDKL5 encephalopathy (n = 10, responder rate = 0.0%, p = 0.031) showed significantly less-favorable responses to KD. Conclusions: The responder rate to KD remained consistent after KD in DEE patients with specific pathogenic mutations. KD is effective in patients with DEE with genetic etiology, especially in patients with SCN1A, KCNQ2, STXBP1, and SCN2A mutations, but is less effective in patients with CDKL5 mutations. Therefore, identifying the causative gene can help predict the efficacy of KD in patients with DEE.