1.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.
2.Recent advances in single-port robotic thyroidectomy:evolution, techniques, and clinical outcomes
Jin Kyong KIM ; Dong Wook KIM ; Jae Sang RYU ; Sungkeun KANG ; Eun Jin KIM ; Sang-Wook KANG ; Jong Ju JEONG ; Kee-Hyun NAM ; Woong Youn CHUNG
Annals of Surgical Treatment and Research 2026;110(1):3-11
Robotic thyroidectomy has progressed from multiport to single-port (SP) platforms to minimize invasiveness and improve cosmesis. The da Vinci SP system (Intuitive Surgical) combines a flexible 3-dimensional endoscope with 3 wristed instruments in a single 2.5-cm cannula-enabled concealed remote access route and mitigates external arm collisions.This review synthesized PubMed-indexed reports (2020–2025) on SP robotic thyroidectomy using the following approaches:transaxillary variants, SP areolar, retroauricular/facelift (SP-hairline variants), and transoral approach. We focused on technical refinement, learning curves, and clinical outcomes. We highlight technical refinements and clinical outcomes across access routes. Contemporary series indicate that SP thyroidectomy is feasible and safe in well-selected patients, with high cosmetic satisfaction and operative metrics comparable to those of multiport cohorts. Among the SP routes, transaxillary variants have the most mature peer-reviewed reporting and are therefore discussed in greater detail. Early applications of SP-assisted lateral neck dissection have also been described. The limitations of current SP platforms include constrained counter-traction, reduced internal workspace, and incomplete integration of advanced energy devices.Nonetheless, ongoing device innovations and the growing global experience suggest that SP systems will increasingly shape endocrine neck surgeries.
3.Whole-Exome Sequencing Improves Risk Assessments of Adult Moyamoya Disease
Eun Pyo HONG ; Eun Jin HA ; Dong Hyuk YOUN ; Yuwhan CHUNG ; Kang Min KIM ; Sung Ho LEE ; Won-Sang CHO ; Hyun-Seung KANG ; Jin Pyeong JEON ; Jeong Eun KIM ;
Journal of Clinical Neurology 2026;22(2):160-172
Background:
and Purpose Whole-exome sequencing (WES) is a valuable tool for identifying causative mutations in adult moyamoya disease (MMD), thereby advancing our understanding of the genetic mechanisms underlying this condition. Here, we conducted the first WESbased association study aimed at identifying genetic modifiers implicated in MMD.
Methods:
This WES study involved 160 patients with MMD and 189 controls from a multicenter hospital-based biobank, and evaluated combined annotation-dependent depletion (CADD) scores. Mutant-allele frequencies were compared in 369,121 individuals derived from the UK Biobank (UKB) WES. Mutant-allele risk scores (MARSs) were created based on WESidentified mutations. Gene-based association analyses and pooled analyses in East-Asian populations were further performed.
Results:
Fourteen mutations reached the genome-wide significance criterion (p<5×10-8 ), among which the p.R4810K mutation in the ring finger protein 213 gene (RNF213) showed the strongest significance (odds ratio=117.4, p=8.54×10-24 ). Notably, two mutations—p.G576S (alpha-glucosidase [GAA]) and p.D54N (charged multivesicular body protein 6 [CHMP6])— exhibited high CADD scores of 32 and 25, respectively, whereas the RNF213 p.R4810K mutation demonstrated a moderate deleteriousness score of 10.63. Fourteen mutations exhibited significant differences in allele frequencies between patients and UKB controlled data (p<1×10-8 ).The MARS9 model (incorporating nine missense mutations) showed better predictability for MMD (90.89%). The analysis of gene-based associations revealed four candidate genes: GAA, RNF213, CHMP6, and CARD14 (p=5×10-19 to 4×10-7 ). The subsequent pooled analyses validated four mutations in East Asian populations: p.V1195M, p.D1331G, p.S2334N, and p.R4810K (p<3×10-8 ).
Conclusions
This pioneering study has corroborated the significance of p.R4810K and identified several causative mutations predisposing patients to MMD, which helps to improve the understanding of its polygenetic nature.
4.Serial KL-6 Changes in PD-1/PD-L1 Inhibitor-Related Pneumonitis in Non-small Cell Lung Cancer: A Single-Center Prospective Pilot Study
Jae Kyeom SIM ; Juwhan CHOI ; Sung Won CHANG ; Sang Hyuk KIM ; Jee Youn OH ; Kyung Hoon MIN ; Gyu Young HUR ; Hwan Seok YONG ; Jae Jeong SHIM ; Sung Yong LEE
Tuberculosis and Respiratory Diseases 2026;89(2):257-265
Background:
Programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) inhibitors are effective treatments for non-small cell lung cancer (NSCLC), but their use can lead to severe pneumonitis. This study aims to evaluate the utility of Krebs von den Lungen-6 (KL-6) for predicting and diagnosing PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients.
Methods:
We conducted a prospective observational study at a university-affiliated tertiary hospital in Korea from February 2022 to June 2023. Baseline KL-6 levels were measured immediately before initiating PD-1/PD-L1 inhibitor therapy. In patients who developed pneumonitis, KL-6 levels were monitored every 1–2 weeks from the onset of pneumonitis. For patients without pneumonitis, KL-6 levels were measured every 6 weeks. We compared clinical characteristics and serial KL-6 levels between the pneumonitis and non-pneumonitis groups.
Results:
Eighteen patients were enrolled, with 11 developing pneumonitis. Baseline KL-6 levels did not significantly differ between the two groups (261 U/mL in the pneumonitis group vs. 373 U/mL in the non-pneumonitis group, p=0.375). In the pneumonitis group, KL-6 levels generally showed an upward trend, with a median of 412 U/mL at pneumonitis onset. Conversely, KL-6 levels in the non-pneumonitis group showed no clear overall change.
Conclusion
In this pilot study, baseline KL-6 was not clearly linked to PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients. However, increases in KL-6 levels post-baseline were more frequently observed in patients who developed pneumonitis, including cases of all-cause pneumonitis.
5.Nationwide Trends in Coronary Artery Bypass Grafting in the Republic of Korea, 2005–2022: A Comparison with International Data
Min Ho JU ; Jun Ho LEE ; Yun Jin KIM ; Ho Jin KIM ; Ho Young HWANG ; Sang Yoon YEOM ; Hee Jung KIM ; Young-Nam YOUN ; Wook Sung KIM ; Man-Jong BAEK ; Hyun Keun CHEE ;
Journal of Chest Surgery 2026;59(1):7-16
Coronary artery bypass grafting (CABG) remains a key revascularization strategy for ischemic heart disease; however, nationwide trends in the Republic of Korea have not been thoroughly investigated. Using data from the Korean National Health Insurance Service, we analyzed adult patients who underwent isolated CABG between 2005 and 2022. We evaluated surgical volume, patient demographics, procedural strategies (off-pump vs. onpump), and outcomes. International comparisons were conducted using national cardiac surgery registry data. A total of 51,923 CABG cases were identified. Annual surgical volume declined until 2013 but gradually increased thereafter, reaching 3,717 cases in 2022. Despite this recovery, Korea’s per capita CABG rate remains among the lowest worldwide.In contrast, more than 60% of procedures were performed off-pump—the highest rate worldwide. Over time, the average patient age and prevalence of diabetes increased, whereas in-hospital mortality showed a modest decline. Compared with other countries, the Republic of Korea demonstrated a uniquely low procedural volume and a strong preference for off-pump CABG. This nationwide analysis highlights Korea’s distinctive CABG practice patterns and provides valuable insights for optimizing future clinical and policy decisions in cardiac surgical care.
6.Korean Red Ginseng and Saponin Regulate the Cytokine and Mucin 5AC/5B Induced by Electronic Cigarette in Respiratory Epithelial Cell
Sang Jae LEE ; Hyung Gyun NA ; Yoon Seok CHOI ; Si-Youn SONG ; Yong-Dae KIM
Korean Journal of Otolaryngology - Head and Neck Surgery 2025;68(1):27-35
Background and Objectives:
Electronic cigarette (e-cigarette) is a device that generate vapor by heating e-cigarettes liquid. E-cigarette damages the respiratory immune system and renders the respiratory tract vulnerable to inflammations. However, there are no studies on how the inflammatory reactions in respiratory epithelial cells caused by e-cigarette occur, and the effects of Korean red ginseng (KRG) and saponin on inflammation induced by e-cigarette are unknown. This study aimed to compare the inflammatory reactions caused by e-cigarette and lipopolysaccharide (LPS), and to investigate the effects of KRG and saponin on cytokine and mucin expression induced by e-cigarette in respiratory epithelial cells.Subjects and Method In bronchoalveolar lavage fluid and lung tissue of mice, the effects of KRG and saponin on cytokines (interleukin [IL]-1β, IL-6, IL-8) and mucin 5AC/5B (MUC5AC/5B) expression induced by e-cigarette were investigated using real-time polymerase chain reaction, enzyme linked immunosorbent assay, and immunohistochemistry staining.
Results:
Inflammatory cells, cytokines (IL-1β, IL-6, IL-8) and MUC5AC/5B messenger RNA expression and protein production were increased by e-cigarette, similar to LPS. KRG and saponin decreased the expression of cytokines (IL-1β, IL-6, IL-8) and MUC5AC/5B induced by e-cigarette. KRG and saponin showed effects similar to that of dexamethasone.
Conclusion
E-cigarette causes inflammation similar to that caused by LPS. KRG and saponin regulate the expression of cytokine and MUC5AC/5B increased by e-cigarette in respiratory epithelial cells. KRG and saponin may be an effective therapeutic option for inflammatory responses induced by e-cigarette in respiratory epithelial cells.
7.Clinical evaluation and management of endometriosis: 2024 guideline for Korean patients from the Korean Society of Endometriosis
Hyun Joo LEE ; Sang-Hee YOON ; Jae Hoon LEE ; Youn-Jee CHUNG ; So Yun PARK ; Sung Woo KIM ; Yeon Hee HONG ; Sung Eun KIM ; Youjin KIM ; Sungwook CHUN ; Yong Jin NA
Obstetrics & Gynecology Science 2025;68(1):43-58
Endometriosis, a prevalent but debilitating condition affecting women, poses significant challenges in diagnosis and management. The current 2024 guideline, developed by the Korean Society of Endometriosis (KSE), builds upon the 2018 KSE guideline. This guideline aims to provide customized recommendations tailored to Korea’s unique clinical aspects and medical environment, and addresses key areas such as diagnosis, medical and surgical management, considerations for special populations, and its complex relationship with cancer.
8.Analysis of the Intra-Nail Location of Nail Psoriasis
Kyungho PAIK ; Bo Ri KIM ; Sang Woong YOUN
Annals of Dermatology 2025;37(1):32-38
Background:
Although nail psoriasis is a common manifestation among patients with psoriasis, large-scale research exploring the association between nail psoriasis lesions and their intra-nail locations has not been conducted. This study is necessary to elucidate the shared pathophysiology among various phenotypes of nail psoriasis.
Objective:
We aimed to understand the association between nail psoriasis lesions and analyze their intra-nail locations.
Methods:
We obtained a total of 5,602 cropped fingernail images from 636 patients with psoriasis. We employed the Computer Vision Annotation Tool to annotate the intra-nail locations of nail psoriasis lesions. We computed χ 2 statistic to examine the relationship between nail psoriasis lesions and conducted an analysis of their intra-nail locations.
Results:
Based on the number of lesions, nail pitting was the most common, followed by leukonychia, with the red spots in the lunula being the rarest. We elucidated the associations between different nail psoriasis lesions, pinpointing a significant association between onycholysis and oil spots (χ 2 statistic=1,623.88), followed by onycholysis-subungual hyperkeratosis (1,607.50), and subungual hyperkeratosis-oil spots (985.76). A spatial relationship was observed between onycholysis and oil spots, with the intra-nail location of onycholysis being more distal compared to the nearest oil spots. A distribution pattern of nail psoriasis was also demonstrated, where nail matrix lesions were primarily located at the center of the nail, and nail bed lesions were predominantly located near the lateral nail folds.
Conclusion
This study represents a pioneering analysis of the intra-nail location of nail psoriasis lesions, revealing substantial associations and spatial relationships between different lesions.
9.Electrical Stimulation Using a Low-Frequency and Low-Intensity Alternating Current Modulates Type I Procollagen Production and MMP-1Expression in Dermal Fibroblasts
Bo Mi KANG ; Jung Min AHN ; Jieun KIM ; Kyungho PAIK ; Bo Ri KIM ; Dong Hun LEE ; Sang Woong YOUN ; Keun-Yong EOM ; Chong Won CHOI
Annals of Dermatology 2025;37(3):152-161
Background:
Despite various therapeutic modalities for keloids have been introduced; however, their therapeutic effects are limited. Therefore, the development of a new approach for inhibiting collagen production by scar fibroblasts is needed.
Objective:
To investigate the effect of electrical stimulation using a low-frequency and low-intensity alternating current on collagen and MMP-1 levels in human dermal fibroblasts.
Methods:
Low-frequency (20 kHz) and low-intensity (1 V/cm) electrical stimulations were applied to primary dermal fibroblasts. The production of type I procollagen and expression of matrix metalloproteinase-1 were evaluated. Transcriptomic analyses were conducted to explore the possible modes of action of electrical stimulation.
Results:
Electrical stimulation effectively suppressed type I procollagen production and increased MMP-1 expression. In addition, transcriptomic analyses revealed that electrical stimulation altered the gene expression associated with membrane permeability and the structure of cellular membranes. Validation using real-time polymerase chain reaction revealed that electrical stimulation significantly altered the expression of mechanosensitive ion channels (PIEZO2) and membrane-bound protein organizing caveolae (CAVIN2).
Conclusion
Electrical stimulation using low-frequency and low-intensity alternating currents effectively modulates extracellular matrix homeostasis by altering the cellular membrane structure and function. Our findings suggest a promising therapeutic approach for the management of keloids and hypertrophic scars.
10.Pancreatic Cancer Detection and Differentiation from Chronic Pancreatitis: Potential Biomarkers Identified Through a High-throughput Multiplex Proteomic Assay and Machine Learning-based Analysis
Young-gon KIM ; Sang-Mi KIM ; Soo-Youn LEE
Annals of Laboratory Medicine 2025;45(4):399-409
Background:
Pancreatic cancer (PC)-screening methods have limited accuracy despite their high clinical demand. Differential diagnosis of chronic pancreatitis (CP) poses another challenge for PC diagnosis. Therefore, we aimed to identify blood protein biomarkers for PC diagnosis and differential diagnosis of CP using high-throughput multiplex proteomic analysis.
Methods:
Two independent cohorts (N = 88 and 80) were included, and residual serum samples were collected from all individuals (N = 168). Each cohort consisted of four groups: healthy (H) individuals and those with CP, stage I/II PC (PC1), or stage III/IV PC (PC2). Protein expression in the first cohort was quantified using the Olink Immuno-Oncology and Oncology 3 proximity extension assay (PEA) panels and was analyzed using machine-learning (ML)-based analyses. Samples in the second cohort were utilized to verify candidate biomarkers in immunoassays.
Results:
Both the PEA and immunoassay results confirmed that previously recognized biomarkers, such as the mucin-16 and interleukin-6 proteins, were more highly expressed in the PC (PC1 and PC2) groups than in the non-PC (CP and H) groups. Several novel biomarkers for PC diagnosis were identified via ML-based feature extraction, including C1QA and CDHR2, whereas pro-neuropeptide Y (NPY) appeared to be a promising biomarker for the differential diagnosis of CP. Applying XGBoost classification incorporating the selected features resulted in an area under the curve of 0.92 (0.85–0.98) for differentiating the PC group from the CP and H groups.
Conclusions
Promising blood biomarkers for PC diagnosis and differential diagnosis of CP were identified using a PEA platform and ML techniques.

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