Background: Copy number variations (CNVs) play an important role in human genetic disorders. Detection of exon-level CNVs is crucial for accurate clinical diagnosis. The CytoScan XON Array, a high-resolution microarray, was recently developed to detect exonic CNVs of various genes. Methods: We evaluated the clinical performance of the CytoScan XON Array using 59 patient samples with previously identified CNVs, confirmed via methods including multiple ligation-dependent probe amplification (MLPA), gene-dose PCR, and mRNA assay. Concordance between CytoScan XON and orthogonal methods was evaluated in target regions, and diagnostic utility was compared with that of genome sequencing (GS)-based CNV calling tools through analysis of false-positive CNVs in non-target genomic regions. Results: For target regions, the CytoScan XON Array achieved concordance rates of 89.8% and 92.5% at the exon and gene levels, respectively, for all CNV calls. Concordance was higher for multi-exon CNVs (100%) than that for single-exon CNVs (82.6%, P = 0.03). For non-target regions, false-positive CNV calls were reduced to fewer than 0.01 per gene per person through filtering strategies. The array exhibited false-positive detection rates within dosage-sensitive genes comparable with those of GS-based tools. Conclusions The CytoScan XON Array, a reliable tool for detecting exon-level CNVs in target regions, can serve as a complementary approach to GS-based CNV calling tools for genome-wide CNV screening with high resolution. However, its performance for single-exon CNVs requires further optimization. Cross-validation with GS-based CNV calling tools is recommended to improve diagnostic accuracy.

Background: Despite widespread vaccination efforts against severe acute respiratory syndrome coronavirus 2, variants with increased transmissibility or immune evasion continue to emerge, posing a considerable challenge. Understanding the immunological factors associated with coronavirus disease (COVID-19) progression is essential for improving patient management and treatment strategies. We explored the dynamic changes in the peripheral white blood cell (WBC) profile, including T lymphocyte subsets, to assess their potential as predictors of disease severity and progression. Methods: Two hundred fifty-eight patients hospitalized for confirmed COVID-19 were classified into four sub-cohorts based on changes in disease severity over 7 days. WBC parameters, including absolute neutrophil, total lymphocyte, and T cell subset counts, and the neutrophil-to-lymphocyte ratio (NLR) were assessed at admission and after 7 days. Results: Patients with persistent mild-to-moderate illness exhibited a marked increase in the lymphocyte count and a decrease in the NLR over time. In contrast, patients with sustained severe-to-critical illness showed an increasing WBC count without a corresponding increase in the lymphocyte count, in addition to a marked elevation in the NLR. Patients whose condition improved from severe-to-critical to mild-to-moderate illness showed increased cluster of differentiation (CD)3+ and CD4+ T cell counts and an elevated CD4/CD8 ratio, whereas the NLR did not significantly change. Conclusions The early-phase dynamics of T cell subsets may serve as a useful biomarker of disease severity and recovery in patients with COVID-19. Monitoring these immunological changes may help support clinical decision-making and inform the timing of therapeutic interventions.

Background: Perfluoroalkyl substances (PFAS) are used in various products, and PFAS have been detected in outdoor clothing. PFAS can be absorbed into the human body via oral ingestion, inhalation, and dermal contact. In this study, we examined the association between the frequency of using outdoor clothing and serum PFAS concentrations in the Korean population using data from cycle 4 (2018–2020) of the Korean National Environmental Health Survey. Methods: Data from 2,993 adult participants were analyzed. The participants were classified into low-concentration and high-concentration groups based on the 75th percentile concentration of serum PFAS. The use of outdoor clothing was categorized into three groups: non-use, <4 times a week, and ≥4 times a week. The odds ratio (OR) for serum PFAS levels associated with use of outdoor clothing was determined through logistic regression analysis, adjusted for demographic characteristics, health-related factors, PFAS-treated items, dietary factors, and ventilation time. Results: ORs for high serum PFAS were higher in groups using outdoor clothing compared to the non-user group. In males, the adjusted ORs for the < 4 times a week and ≥ 4 times a week outdoor clothing usage group were as follows: perfluorooctanoic acid (PFOA), 1.26 (95% confidence interval [CI]: 1.10–1.44) and 1.70 (1.40–2.07); perfluorohexanesulfonic acid (PFHxS), 1.49 (1.16–1.92) and 1.70 (1.22–2.37); and perfluorononanoic acid (PFNA), 1.34 (1.19–1.51) and 1.68 (1.38–2.05), respectively. In females, the respective ORs were as follows: PFOA 1.32 (95% CI: 1.19–1.46) and 1.53 (1.01–2.32); PFHxS, 1.46 (1.08–1.96) and 2.63 (2.10–3.29); PFNA, 1.38 (1.22–1.55) and 1.45 (1.07–1.96). Conclusions In adults, elevated serum PFAS levels were associated with increased frequency of using outdoor clothing.

Objective: To evaluate the effectiveness of the National Health Screening Program for Infants and Children (NHSPIC) in the early diagnosis of neurodevelopmental disorders (NDDs) utilizing data from the National Health Insurance Database of South Korea. Methods: We enrolled children born between 2011 and 2018 who completed the first to fourth stages of the NHSPIC. A positive finding was defined as a recommendation for further evaluation during one or more stages. Participants were categorized into the positive and negative finding groups. Following 1:1 propensity score matching, 82,138 participants were assigned to each group. Results: Comparative analysis revealed that participants with positive findings exhibited a higher risk of developing all seven NDDs, particularly for autism spectrum disorder (hazard ratio [HR], 19.70; 95% confidence interval [CI], 17.48–22.20), intellectual disability (HR, 17.11; 95% CI, 14.69–19.93), developmental language disorder (HR, 11.74; 95% CI, 10.73– 12.84), and cerebral palsy (HR, 11.34; 95% CI, 8.67–14.84). The HR for learning disability was 4.31 (95% CI, 2.94–6.34), whereas attention-deficit hyperactivity disorder had an HR of 3.57 (95% CI, 3.37–3.78). Tic disorder had the lowest HR (HR, 1.64; 95% CI, 1.48–1.82). Additionally, HRs were calculated for each NHSPIC stage, demonstrating the utility of specific stages in the early detection of each NDD. Conclusion Developmental screening tests in the NHSPIC contributed to the early diagnosis of NDDs. This study underscores the significance of the NHSPIC and provides foundational evidence to inform and enhance policies related to child health screenings.

Purpose: Esophagojejunal anastomotic leakage (EJAL) represents a severe postoperative complication following total or proximal gastrectomy. Treatment strategies include conservative management, endoscopic interventions, and surgery; however, comparative data remain limited. This study aimed to compare clinical outcomes of different strategies to identify the optimal approach based on anastomotic defect size. Materials and Methods: This retrospective study reviewed 100 patients diagnosed with EJAL between January 2015 and October 2024. Patients were categorized into four groups:conservative management, endoscopic vacuum-assisted closure (E-VAC), other endoscopic treatments, and surgery. The primary outcomes were leakage duration and length of hospital stay after EJAL diagnosis, whereas the secondary outcome was time to C-reactive protein normalization. Subgroup analyses were performed according to defect size. Results: Among the 100 patients, 76 were male and 24 were female, with a mean age of 65.7 years. Conservative treatment was the most common modality (53%), followed by other endoscopic treatments (19%), E-VAC (14%), and surgery (14%). In patients with a defect size <1 cm, conservative treatment was associated with significantly shorter leakage duration (P=0.035) and earlier resumption of diet (P=0.029) compared with endoscopic treatment.Among those with defects ≥2 cm, E-VAC demonstrated the most favorable median outcomes across all variables; however, statistical significance was not achieved because of the small sample size. Conclusions Conservative treatment appears to be the most effective treatment strategy for EJAL with anastomotic defects <1 cm. For larger defects (≥2 cm), E-VAC may offer clinical benefit, although further studies are needed to confirm its efficacy. These findings highlight the importance of individualized treatment selection based on defect size.

Amputation in the context of infectious and ischemic foot and ankle diseases, including diabetic foot, Buerger’s disease, arteriosclerosis obliterans, and frostbite, demands a reconstructive approach aimed at functional restoration rather than mere disease removal. Surgical success depends on meticulous debridement, tension-free closure, strategic determination of the amputation level based on vascular assessment, and staged management of concurrent infection. Proper tourniquet use, preservation of viable soft tissue, including plantar skin flaps, appropriate wound closure, and the judicious use of skin grafts and flap surgery are fundamental principles. Vascular evaluation, including Doppler ultrasonography and transcutaneous oxygen pressure measurement, guides the amputation plane. Optimizing the nutritional status and glycemic control is critical in the diabetic population. Beyond the surgical technique, the psychosocial burden on patients and caregivers demands a multidisciplinary approach incorporating psychological support and social services. Clear, documented informed consent that specifically addresses the intraoperative level change and re-amputation risk is an ethical obligation and an essential legal safeguard. A successful outcome requires balancing limb salvage with functional restoration while addressing the clinical, psychological, and legal complexities of these cases.

Purpose: The Dietary Reference Intakes for Koreans (KDRIs) serve as a foundation for nutrition policy, nutrition education, and dietary intake evaluation among healthy Koreans.The KDRIs are revised every five years to ensure that the guidelines are based on a robust and up-to-date scientific foundation. For the 2025 KDRIs for calcium, the 2020 KDRIs were revisited, and references were critically evaluated. Methods: All references cited in the 2020 KDRIs were extracted, reviewed, and organized according to the framework for the estimated average requirement (EAR). Each reference was evaluated based on the participant characteristics, including age, race/ethnicity, and health status, as well as study design, exposure, and outcomes. In addition, calculations for the EAR and Recommended Nutritient Intakes were re-examined for each sex and age group and compared with the current literature. Results: Major revisions in the 2025 KDRIs were driven by updates in the reference bodyweight, improved consistency in rounding and coefficients of variation, inclusion of studies in East Asian populations, and clarification of the use of calcium balance studies.Nevertheless, further studies in Koreans, particularly in pregnant and lactating women, are needed to strengthen the scientific evidence for the calcium DRI. Conclusion The 2025 KDRIs for calcium were revised to be based on more robust logical reasoning and calculation methods. Future research conducted on Korean populations is necessary to define the calcium requirements for Koreans more accurately.

Objectives: Ischemic stroke is influenced by long-term metabolic and renal deterioration; however, many risk prediction frameworks rely on single time-point measurements. We examined whether multi-period patterns in national health screening indicators are associated with incident ischemic stroke in Korea. Methods: Using customized National Health Insurance Service data with 3 biennial screenings (P1: 2013–2014; P2: 2015–2016; P3: 2017–2018), we identified incident ischemic stroke during 2019–2023 (Korean Standard Classification of Diseases-7 I63). After applying eligibility criteria and excluding individuals with missing screening values, we performed 1:1 propensity score matching on sex, 1-year age strata, and insurance type (97 454 matched pairs; n=194 908). Multi-period indicators included waist circumference increase ≥10%, sustained blood pressure ≥130/80 mmHg, sustained fasting glucose ≥126 mg/dL, proteinuria progression, and creatinine elevation in ≥2 periods (sex-specific thresholds). Associations were evaluated using conditional logistic regression; a comparator model used P3-only indicators. Results: In the multi-period model, stroke was associated with waist circumference increase ≥10% (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01 to 1.08), sustained blood pressure ≥130/80 mmHg (OR, 1.34; 95% CI, 1.31 to 1.37), sustained fasting glucose ≥126 mg/dL (OR, 1.66; 95% CI, 1.60 to 1.73), creatinine elevation in ≥2 periods (OR, 1.08; 95% CI, 1.06 to 1.10), and proteinuria progression (OR, 1.36; 95% CI, 1.32 to 1.39). In the P3-only model, all single-time-point indicators were associated with incident stroke (ORs, 1.08 to 1.47). Conclusions Multi-year patterns in metabolic screening indicators were associated with incident ischemic stroke. Repeated health screening measurements may complement single time-point assessments and support continuous risk-factor monitoring and patient-centered prevention.