Inborn errors of immunity (IEI) include a variety of heterogeneous genetic disorders in which defects in the immune system lead to an increased susceptibility to infections and other complications. Accurate, prompt diagnosis of IEI is crucial for treatment plan and prognostication. In this study, clinical utility of clinical exome sequencing (CES) for diagnosis of IEI was evaluated. For 37 Korean patients with suspected symptoms, signs, or laboratory abnormalities associated with IEI, CES that covers 4,894 genes including genes related to IEI was performed. Their clinical diagnosis, clinical characteristics, family history of infection, and laboratory results, as well as detected variants, were reviewed. With CES, genetic diagnosis of IEI was made in 15 out of 37 patients (40.5%). Seventeen pathogenic variants were detected from IEI-related genes, BTK , UNC13D, STAT3 , IL2RG , IL10RA , NRAS, SH2D1A, GATA2, TET2, PRF1 , and UBA1 , of which four variants were previously unreported. Among them, somatic causative variants were identified from GATA2, TET2 , and UBA1 . In addition, we identified two patients incidentally diagnosed IEI by CES, which was performed to diagnose other diseases of patients with unrecognized IEI. Taken together, these results demonstrate the utility of CES for the diagnosis of IEI, which contributes to accurate diagnosis and proper treatments.
Abstract Objectives Clonal hematopoiesis (CH) is a condition in which healthy individuals have somatic mutations in hematopoietic stem cells. It has been reported with increased risk of hematologic malignancy and cardiovascular disease in the general population, but studies of Korean populations with comorbid disease entities are scarce. Methods White blood cells (WBCs) from patients with gastric cancer (GC) (n=121) were analyzed using a DNA-based targeted (531 genes) panel with customized pipeline designed to detect single nucleotide variants and small indels with low-allele-frequency of ≥0.2 %. We defined significant CH variants as having variant allele frequency (VAF) ≥2 % among variants found in WBCs. Matched cell-free DNA (cfDNA) samples were also analyzed with the same pipeline to investigate the false-positive results caused by WBC variants in cfDNA profiling. Results Significant CH variants were detected in 29.8 % of patients and were associated with age and male sex. The number of CH variants was associated with a history of anti-cancer therapy and age. DNMT3A and TET2 were recurrently mutated. Overall survival rate of treatment-naïve patients with stage IV GC was higher in those with CH, but Cox regression showed no significant association after adjustment for age, sex, anti-cancer therapy, and smoking history. In addition, we analyzed the potential interference of WBC variants in plasma cell-free DNA testing, which has attracted interest as a complementary method for tissue biopsy. Results showed that 37.0 % (47/127) of plasma specimens harbored at least one WBC variant. VAFs of interfering WBC variants in the plasma and WBC were correlated, and WBC variants with VAF ≥4 % in WBC were frequently detected in plasma with the same VAF. Conclusions This study revealed the clinical impact of CH in Korean patients and suggests the potential for its interference in cfDNA tests.
Background: Unlike therapy-related myeloid neoplasms, therapy-related acute lymphoblastic leukaemia (tr-ALL) is poorly defined due to its rarity. However, increasing reports have demonstrated that tr-ALL is a distinct entity with adverse genetic features and clinical outcomes. Methods: We compared the clinicopathological characteristics and outcomes of patients diagnosed with tr-ALL (n = 9) or de novo ALL (dn-ALL; n = 162) at a single institution from January 2012 to March 2021. The mutational landscapes of eight tr-ALL and 63 dn-ALL patients were compared from a comprehensive next-generation sequencing panel. Results: All tr-ALL patients had the B-cell phenotype. The most frequently mutated genes were IKZF1 (37%), CDKN2A (14%), SETD2 (13%), and CDKN2B (11%) in dn-ALL, whereas TP53 (38%) and RB1 (25%) mutations were most common in tr-ALL. tr-ALL patients did not show a statistically significant difference in overall survival (p = 0.70) or progression-free survival (p = 0.94) compared to dn-ALL patients. Conclusions: In this study, we determined the clinical and genetic profiles of Korean patients with tr-ALL. We found alterations in genes constituting the TP53/RB1 pathway are more frequent in tr-ALL. Due to the rarity of the disease, multi-institutional studies involving a larger number of patients are required in future study.
Abstract Background BCR::ABL1 fusion has significant prognostic value and is screened for chronic myeloid leukaemia (CML) disease monitoring as a part of routine molecular testing. To overcome the limitations of the current standard real-time quantitative polymerase chain reaction (RQ-PCR), we designed and validated a next-generation sequencing (NGS)-based assay to quantify BCR::ABL1 and ABL1 transcript copy numbers. Methods After PCR amplification of the target sequence, deep sequencing was performed using an Illumina Nextseq 550Dx sequencer and in-house–designed bioinformatics pipeline. The Next-generation Quantitative sequencing (NQ-seq) assay was validated for its analytical performance, including precision, linearity, and limit of detection, using serially diluted control materials. A comparison with conventional RQ-PCR was performed with 145 clinical samples from 77 patients. Results The limit of detection of the NQ-seq was the molecular response (MR) 5.6 [ BCR::ABL1 0.00028% international scale (IS)]. The NQ-seq exhibited excellent precision and linear range from MR 2.0 to 5.0. The IS value from the NQ-seq was highly correlated with conventional RQ-PCR. Conclusions We conclude that the NQ-seq is an effective tool for monitoring BCR::ABL1 transcripts in CML patients with high sensitivity and reliability. Prospective assessment of the unselected large series is required to validate the clinical impact of this NGS-based monitoring strategy.