1.Applying National Whole-genome Sequencing Findings for Rare Diseases in Clinical Practice: The Imperative of a Multidisciplinary Approach
Kyung Sun PARK ; Sunghwan SHIN ; Jong-Ho PARK ; Young-Eun KIM ; Won Kyung KWON ; Min-Kyung SO ; Changhee HA ; Ja-Hyun JANG ; Taeheon LEE ; Chang-Seok KI ; Yoonjung KIM ; Kyung-A LEE ; Inho PARK ; Sejoon LEE ; Hong-Hee WON ; ; Jong-Won KIM
Annals of Laboratory Medicine 2026;46(1):94-103
Background:
As nationwide government-led whole-genome sequencing (WGS) projects progress, optimizing the clinical integration of large-scale WGS results is crucial. We explored how the initial analysis from Korea’s First WGS Pilot Study for Rare Diseases was applied in clinical practice, and then we reanalyzed the data comprehensively at Samsung Medical Center (SMC) Seoul, Korea.
Methods:
A prospective cohort study designed to collect WGS data under a Korean national initiative was conducted from August 2020 to December 2021. We focused on patients with rare diseases recruited from 16 university hospitals. The participants included 5,000 individuals (2,200 probands and 2,800 family members). The initial WGS data and diagnostic reference reports (from 682 probands and 484 family members), generated based on the First Korean WGS Pilot Study for Rare Diseases, were subsequently reanalyzed by SMC.
Results:
The initial analysis of the First Korean WGS Pilot Study data revealed a diagnostic rate of 17%. Upon receiving these results, the SMC conducted two rounds of reanalysis, increasing the diagnostic rate from 15% in the first analysis, to 18% in the second, and finally to 24% in the third (P = 1.6 × 10 −5 ). Key factors in improving the genetic diagnosis included increased detection of novel (likely) pathogenic variants (P = 1.0 × 10 −4 ), improved diagnostic rates with larger family recruitment (P = 0.004), and refined clinical information for more precise genotype–phenotype correlation analysis (40%).
Conclusions
Although national WGS projects lay a foundation for rare disease diagnosis, hospital-level reanalysis and multidisciplinary collaborations are crucial for optimizing diagnostic outcomes.
2.Age-Stratified Genetic Spectrum of Retinitis Pigmentosa in Korean Patients: Predominance of RPGR Variants in Early-Onset Disease
Youn-Ji HONG ; Sungsoon HWANG ; Ja-Hyun JANG ; Jong-Won KIM ; Sang Jin KIM ; Mi-Ae JANG
Annals of Laboratory Medicine 2026;46(2):200-209
Background:
Retinitis pigmentosa (RP) comprises a heterogeneous group of inherited retinal dystrophies. The genetic landscape of RP has been characterized; however, knowledge gaps regarding age-specific genetic variation trends in Korean patients remain. We comprehensively characterized the age-stratified genetic landscape of RP in Korean patients, with a focus on identifying novel mutational trends and clinically actionable insights.
Methods:
We performed targeted next-generation sequencing of 199 genes associated with RP and related disorders in a cohort of 403 unrelated patients clinically diagnosed as having RP. We analyzed the inheritance patterns, variation spectrum, and prevalence of pathogenic variants, stratifying the results by age, and conducted copy number variation (CNV) analysis.
Results:
A genetic diagnosis was achieved for 193 of the 403 patients (48%). The diagnostic yield was highest in patients diagnosed before 20 yrs of age (60%), with lower yields in older age groups. Although USH2A and EYS, the most common causative genes in autosomal recessive inheritance, were frequently identified, RPGR pathogenic variants accounted for a significantly larger proportion of genetically solved cases diagnosed before the age of 20 yrs (27%–28%) than in those with later-onset disease (9%–15%). CNVs were identified in 4% of genetically solved cases.
Conclusions
The results underscore distinct, age-related genetic contributions to RP in Korean patients, with RPGR variants demonstrating relevance in early-onset disease, and provide diagnostic insights to improve current practices. These findings can aid in prioritizing gene therapy targets and refining screening strategies.
3.Development and qualitative validation of a virtual reality simulation program for managing behavioral and psychological symptoms of dementia and delirium superimposed on dementia: A pilot study
Young Jin KIM ; Kyoung Ja MOON
Journal of Korean Gerontological Nursing 2026;28(1):74-87
Behavioral and psychological symptoms of dementia (BPSD) and delirium superimposed on dementia (DSD) can lead to severe complications if they are not accurately identified and managed. Effective dementia care therefore requires clear differentiation, systematic assessment, and appropriate nursing interventions. This study aimed to develop VRDementia: BPSD/DSD, a virtual reality simulation program, and to qualitatively examine its validity and usability as a development-based pilot study. Methods: Using the ADDIE model (Analysis, Design, Development, Implementation, Evaluation), the program was systematically developed. During the analysis phase, qualitative interviews and literature reviews identified educational needs among nurses in long-term care hospitals. Key challenges included distinguishing agitation/aggression (BPSD) from hyperactive DSD, and depression (BPSD) from hypoactive DSD. Based on these findings, four case-based scenarios were created. Content validity and usability were qualitatively evaluated through semi-structured interviews with five experienced nurses (≥5 years of clinical experience). Results: The program consists of four sessions addressing agitation/aggression and depression (BPSD), and hyperactivity and hypoactivity (DSD). Nurses practice symptom assessment, therapeutic communication, physician reporting, and nursing interventions. The simulation is accessible via head-mounted display (HMD), mobile devices, and PC (including laptops). Qualitative feedback indicated that participants perceived the program as useful and applicable for dementia care education, including its potential use in interdisciplinary training contexts. Conclusion: VRDementia: BPSD/DSD is a valid, practical educational tool that improves nurses’ competence in distinguishing and managing BPSD and DSD. This program may contribute to higher quality dementia care in clinical settings.
4.Main revisions to carbohydrate intake reference values in the 2025 Dietary Reference Intakes for Koreans
Miae DOO ; YoonJu SONG ; Jeong Hyun LIM ; Ja Young JEON ; Wookyoung KIM
Journal of Nutrition and Health 2026;59(2):148-158
The recommendations for carbohydrate intake were revised in the 2025 Korean Dietary Reference Intakes to reflect updated evidence on chronic disease risk and to clarify the interpretation of the Estimated Average Requirement (EAR) and Recommended Nutrient Intake (RNI). These revisions aim to strengthen both the scientific basis and the practical interpretation of carbohydrate intake guidance across the life course of an individual. For individuals aged 1 year and older, the Acceptable Macronutrient Distribution Range for carbohydrates was lowered from 55–65% of total energy to 50–65%. This adjustment reflects accumulating evidence from prospective cohort studies and meta-analyses indicating that very high carbohydrate intake is associated with an increased risk of adverse health outcomes. In contrast, an intake of approximately 50–55% of total energy is associated with the lowest mortality risk. Importantly, this change does not imply a preference for low-carbohydrate diets, as overall dietary quality, including carbohydrate quality, remains a critical consideration. The EAR (100 g/day) and RNI (130 g/day) are derived from estimates of brain glucose utilization and metabolic adaptation and should be interpreted as physiological minimum intake levels rather than population-based intake targets. In addition, life-stage-specific recommendations were updated based on new evidence, including recalculating the Adequate Intake (AI) for infants (55 g/day for 0–5 months and 85 g/day for 6–11 months) and revising the additional requirements during pregnancy (+35 g/day) and lactation (+55 g/day).Because no Tolerable Upper Intake Level (UL) has been established for total carbohydrate intake, excess intake should be managed through dietary adjustments, including limiting added sugars and refined carbohydrates, ensuring adequate fiber intake, and maintaining overall macronutrient balance. Collectively, these revisions provide an updated evidencebased framework for carbohydrate intake guidance for the Korean population.
5.3-Dimensional reconstruction reveals frequent intraluminal growth of submucosal veins in surgically resected pT1 colorectal cancers
Jihyun PARK ; Mi-Ju KIM ; Yeon Wook KIM ; Byong-Wook LEE ; Junyoung SHIN ; Jinho SHIN ; Chan-Gi PACK ; Dong-Hoon YANG ; Jihun KIM ; In Ja PARK ; Ralph H. HRUBAN ; Seung-Mo HONG
Journal of Pathology and Translational Medicine 2026;60(2):246-262
Although venous invasion (VI) is associated with distant metastasis and observed in >50% of pT2–4 colorectal cancers (CRCs), the role of VI in pT1 CRCs is not well-defined. Methods: Thirty-four surgically resected pT1 CRCs were reevaluated for 2-dimensional (2D) VI using hematoxylin and eosin (H&E)–stained slides with additional elastic and desmin immunohistochemical staining (cohort A). Additionally, 27 pT1 CRCs without knowing VI status were selected for 3-dimensional (3D) VI evaluation only (cohort B). All 61 cases (cohorts A and B) were studied in 3D using tissue clearing. Results: VI was detected more commonly in 3D (17/34, 50.0%) than in 2D H&E slide evaluation (9/34, 26.5%, p = .047). When VI was identified in 3D (27/61, 44.3%), the most common phase was that of intraluminal growth (22/27, 81.5%), followed by intravasation (7/27, 25.9%) and extravasation (5/27, 18.5%). E-cadherin expression was characterized in 3D in foci of VI and varied in each phase of invasion. Conclusions: All three phases were observed in VI of pT1 CRCs. The extravasation of neoplastic cells from foci of VI in pT1 CRC suggests that VI could be a route of intratumoral spreading in a subset of pT1 CRCs.
6.HER2-low and ultralow breast cancer: interobserver challenges and lessons from a consensus study
Jiwon KOH ; Yoon Jin CHA ; Eun Yoon CHO ; Ahwon LEE ; Ja Seung KOO ; So Yeon PARK ; Min Hwan KIM ; Jae Ho JEONG ; Gyungyub GONG
Journal of Pathology and Translational Medicine 2026;60(3):331-337
The recent approval of trastuzumab deruxtecan for human epidermal growth factor receptor 2 (HER2)–low and HER2-ultralow breast cancer mandates an adequate assessment of these categories. Methods: Seven breast pathologists from the Breast Pathology Study Group of the Korean Society of Pathologists held an on-site expert consensus meeting. Fifteen sets of virtual whole slide images (WSI) of hematoxylin and eosin stain and HER2 immunohistochemistry were provided. The pathologists were given 60 minutes to submit their diagnosis of HER2 expression into null, ultralow, 1+, 2+, or 3+. Afterwards, in-depth discussion and consensus diagnoses were made by real-time visualization of the WSI. Results: After the consensus meeting, unanimous 100% agreements were seen only in five (33.3%) of the examined cases, which consisted of three 1+ cases and two 2+ cases. Two cases (13.3%) had mild disagreement, with only one pathologist’s disagreement. Of note, eight cases (53.3%) showed significant disagreement, defined by more than two pathologists’ disagreement. All HER2-null cases were reclassified as ultralow after consensus review, suggesting potential widespread underclassification of ultralow cases in clinical practice. Conclusions: Experts had significant discrepancies in interpreting HER2-low/ultralow status. It is important to assess if the distinction between HER2-low and ultralow is strictly required and if HER2-null breast cancer exists in reality.
7.An Analysis of Judicial Precedents on Medical Practice in Criminal Litigation in Obstetrics and Gynecology
Jeong Hyeon LEE ; Jun Won PARK ; Joon Cheol PARK ; Dong Ja KIM
Korean Journal of Medical Ethics 2026;29(1):31-47
This study analyzed 22 criminal cases involving obstetricians and gynecologists to identify legal trends and propose measures to reduce the legal burden on medical professionals while maintaining stable healthcare services. The cases were retrieved from the Supreme Court of Korea Judicial Information Disclosure Portal using keywords such as “obstetrics,” “gynecology,” “expectant mother,” “fetus,” “neonate,” “delivery,” “uterus,” and “placenta.” The cases were classified into two categories:medical malpractice (16 cases, 72.7%) and abortion and bioethics (6 cases, 27.3%). Guilty verdicts were issued in 8 cases (36.4%), whereas 14 cases (63.6%) resulted in acquittal. The qualitative analysis showed that courts consistently protected physicians’ clinical discretion in unpredictable and unavoidable situations, such as amniotic fluid embolism and uterine atony, provided that standard medical protocols were followed. Procedural appropriateness, rather than the perfection of clinical outcomes, appeared to be the primary basis for judicial protection. Although the judiciary acknowledges the inherent limitations of medical practice and tends to protect physicians when established guidelines are followed, the high frequency of criminal prosecution remains a substantial burden on healthcare providers and may threaten the sustainability of obstetric care.
8.Prognostic Impact of Radiologic and Pathologic Features on the Development of Progressive Pulmonary Fibrosis in Patients With Interstitial Lung Disease Other Than Idiopathic Pulmonary Fibrosis
Hyeong Ryun CHO ; Myoung Ja CHUNG ; Hyemi CHOI ; Jinheum KIM ; Ae Ri AN ; Su Yeon AHN ; Jin Young YOO ; Gong Yong JIN ; David A LYNCH ; Kum Ju CHAE
Korean Journal of Radiology 2026;27(1):63-75
Objective:
To evaluate the prognostic impact of radiologic and pathologic features in patients with interstitial lung disease (ILD) other than idiopathic pulmonary fibrosis (IPF), and to identify the factors associated with the development of progressive pulmonary fibrosis (PPF) and survival.
Materials and Methods:
This study retrospectively enrolled 75 patients diagnosed with ILD other than IPF who underwent surgical lung biopsy between January 2004 and December 2020. Three chest radiologists independently reviewed the CT features and extent of fibrosis on preoperative and follow-up CT scans. Two pathologists reviewed the histopathological features, including the presence of interstitial pneumonia. The time to PPF and overall survival were estimated using the Kaplan-Meier method. The associations of CT and pathological features with PPF and all-cause mortality were examined using standard Cox regression and time-dependent Cox models, respectively.
Results:
A total of 75 non-IPF ILD patients (mean age ± standard deviations 56.4 ± 13.2 years; range, 40–88 years) were enrolled. The median follow-up duration was 75.3 months (range, 7.8–189.8 months). Traction bronchiectasis on CT (adjusted hazard ratio [HR], 6.40; P = 0.003) and body mass index (adjusted HR per 1-kg/m2 increase, 0.82; P = 0.002) were found to be significantly associated with PPF in multivariable analysis. Radiological progression (adjusted HR, 18.44;P < 0.001), symptomatic progression (adjusted HR, 4.19; P = 0.011), and age (adjusted HR for 1-year increase, 1.12; P < 0.001) were significantly associated with death.
Conclusion
Traction bronchiectasis on CT was a significant predictor of PPF, while radiologic and symptomatic progression and older age were associated with poorer survival in patients with ILD other than IPF. These findings indicate that careful radiological evaluation and symptom monitoring may help to predict disease progression and outcomes in patients with nonIPF ILD.
9.Deep Learning–Based Bone Age Assessment for Predicting Final Adult Height in Girls With Central Precocious Puberty
Jeong Min SONG ; Pyeong Hwa KIM ; Young Ah CHO ; Ah Young JUNG ; Jin Seong LEE ; Ja Hye KIM ; Hee Mang YOON
Korean Journal of Radiology 2026;27(6):568-577
Objective:
This study aimed to evaluate the accuracy of predicting final adult height (FAH) in Korean girls with central precocious puberty (CPP) using artificial intelligence (AI)-derived bone age assessments integrated into the Bayley–Pinneau (BP) or Korean National Growth Chart (KGC) prediction models.
Materials and Methods:
This single-center, retrospective study included 122 Korean girls with CPP who received gonadotropinreleasing hormone agonist (GnRHa) treatment for at least two years between January 2000 and November 2022. We assessed bone age and predicted adult height at the initiation and completion of GnRHa treatment. We used three bone age assessment methods: human expert assessment based on the Greulich-Pyle (GP) atlas (Human-GP), AI-derived GP (AI-GP), and AI-weighted GP scoring (AI-GPw). We calculated predicted adult heights (PAHs) using both the BP and KGC models, generating 12 PAH estimates per patient (2 time points x 3 bone-age methods x 2 height-prediction models). We assessed prediction accuracy and agreement with FAH using linear regression analysis and Bland–Altman plots and performed multivariable analysis to identify significant predictors of FAH.
Results:
Human-GP, AI-GP, and AI-GPw demonstrated comparable overall performance in predicting FAH (R 2 : 0.470–0.646 and 0.691–0.822 for treatment initiation and completion, respectively). AI-GPw combined with BP yielded slightly better point estimates but showed no statistically significant differences. At both time points, the BP model demonstrated consistently narrower 95% limits of agreement (LoA) than the KGC model. Multivariable analysis identified AI-GPw-BP and height percentile score as significant predictors of FAH at both time points; mid-parental height was significant only at treatment initiation.
Conclusion
Human-GP, AI-GP, and AI-GPw demonstrated comparable accuracy in predicting FAH. The BP model demonstrated consistently narrower 95% LoA than did the KGC model. AI-GPw-BP was an independent predictor of FAH. These findings support the clinical utility of AI-derived bone age assessments for individualized FAH prediction in patients with CPP.
10.Bowel preparation for colonoscopy in special populations: a practical and risk-stratified approach
Myung-Hun LEE ; Won MOON ; Kyoungwon JUNG ; Jae Hyun KIM ; Sung Eun KIM ; Moo In PARK ; Seun Ja PARK
Kosin Medical Journal 2026;41(1):9-18
Bowel preparation is a key determinant of colonoscopy quality; however, inadequate cleansing remains common among patients with overlapping clinical and logistical barriers. In routine practice, preparation failure may prolong procedures, reduce diagnostic confidence, and necessitate early repeat colonoscopy. We review major society guidelines and selected studies addressing bowel preparation in inflammatory bowel disease (IBD), chronic kidney disease (CKD), older adults, chronic constipation, and hospitalized patients. Across these settings, the most consistently supported measures include split-dose administration, completion of the final dose close to the time of colonoscopy in accordance with local fasting and sedation policies, and structured patient instructions reinforced through follow-up communication. A standardized assessment of preparation quality is recommended to support quality improvement and appropriate follow-up. Risk stratification can help identify patients who may benefit from intensified preparation pathways, including those with prior inadequate preparation, severe constipation, frailty, or inpatient status. Safety considerations are particularly important in CKD, in which oral sodium phosphate should be avoided and magnesium-containing agents used cautiously; polyethylene glycol-based solutions are generally preferred. In IBD, regimen selection should also consider endoscopic interpretability because sodium phosphate preparations have been associated with preparation-related mucosal abnormalities that may confound the assessment of subtle inflammatory findings. Among hospitalized patients, system-level barriers often predominate, and protocolized pathways may improve workflow and patient comfort while maintaining cleansing effectiveness. We propose a practical, risk-stratified approach to regimen selection, timing, rescue strategies, and safety monitoring that can be implemented in high-volume clinical practice.

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