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.Impact of Intraoperative Parathyroid Hormone Monitoring on Surgical and Biochemical Outcomes in Tertiary Hyperparathyroidism: A Retrospective Cohort Study
Suh Yun CHUNG ; Young-min LEE ; Sookyung KIM ; Byung-Chang KIM ; Won Woong KIM ; Yu-mi LEE ; Tae-Yon SUNG ; Ki-Wook CHUNG
Journal of Endocrine Surgery 2026;26(1):9-20
Purpose:
Persistent hypercalcemia after parathyroidectomy (PTx) remains a significant concern in patients with tertiary hyperparathyroidism (THPT) following kidney transplant (KT). Complete resection of hyperfunctioning glands is challenging due to ectopic or intrathyroidal glands. This study evaluated whether intraoperative parathyroid hormone (ioPTH) monitoring during PTx in KT patients with THPT reduces the surgical failure rate.
Methods:
We retrospectively analyzed 111 patients with THPT who underwent PTx at a single tertiary center. Patients were divided into 2 groups: those without ioPTH monitoring (n=98) and those with ioPTH monitoring (n=13). Surgical procedures included less than subtotal, subtotal, or total PTx with autotransplantation. Surgical failure was defined as persistent hypercalcemia (serum calcium ≥10.3 mg/dL and intact parathyroid hormone [PTH] >65 pg/mL) on postoperative day 1 (POD1) or at ≥6 months postoperatively.
Results:
The ioPTH group demonstrated a significantly lower mean PTH level on POD1 (21±15.3 pg/mL vs. 39±39 pg/mL; P=0.006). Although not statistically significant, the ioPTH group showed a higher biochemical cure rate at 3 months (53.8% vs. 30.6%) and no cases of persistent hyperparathyroidism, compared to 15.3% in the non-ioPTH group.Despite adequate intraoperative PTH reduction, some patients in both groups exhibited isolated PTH elevation without hypercalcemia.
Conclusion
Although ioPTH monitoring did not significantly reduce the surgical failure rate in PTx for THPT, the use of ioPTH may meaningfully improve surgical completeness and reduce the risk of persistent or recurrent hyperparathyroidism, suggesting its substantial potential value as an intraoperative.
3.Online DPPH Assay Coupled with LC-QTOF-MS for Rapid Identification of Antioxidant Constituents from Zelkova serrata
Ngoc Khanh VU ; Chang Jung KIM ; Soo Min KIM ; Young Jun KIM ; Kyeong Seon LEE ; Ki Yong LEE
Natural Product Sciences 2026;32(1):29-37
Zelkova serrata (Thunb.) Makino is a deciduous tree commonly distributed in East Asia. Several investigations have documented the biological activity of extracts of this species, igniting increased interest in its therapeutic potential. However, the phytochemical constituents accountable for these activities remain largely unexplored. In this study, we focused on the antioxidant potential of the leaves and twigs, utilizing bioactivityguided fractionation combined with LC-QTOF-MS online DPPH screening to systematically identify the active compounds. This approach led to the isolation of eight compounds, three of which (compounds 1, 3, and 7) have not previously been documented in the genus Zelkova. Among the isolates, 4 emerged as the most potent antioxidant, exhibiting significant radical scavenging activity in both DPPH (IC 50 = 13.67 ± 1.21 μM) and ABTS (IC50 = 2.69 ± 0.48 μM) assays, exceeding ascorbic acid (IC 50 = 61.51 ± 10.22 μM) and trolox (IC50 = 8.22 ± 2.16 μM), respectively. Our findings not only enrich the phytochemical profile of Z. serrata but also highlight the effectiveness of LC-MS-DPPH as an effective approach for rapid antioxidant discovery.
4.Hungry bone syndrome after parathyroidectomy in secondary and tertiary hyperparathyroidism:a retrospective cohort study
Douk KWON ; Byung-Chang KIM ; Yu-mi LEE ; Tae-Yon SUNG ; Ki-Wook CHUNG ; Won Woong KIM
Annals of Surgical Treatment and Research 2026;110(3):149-156
Purpose:
Hungry bone syndrome (HBS) is a common and critical postoperative complication in patients undergoing parathyroidectomy (PTX) for secondary hyperparathyroidism (SHPT) and tertiary hyperparathyroidism (THPT). We aimed to identify clinical predictors of HBS and assess its impact on bone mineral density (BMD) after PTX.
Methods:
We retrospectively analyzed data of patients with SHPT and THPT who underwent PTX at Asan Medical Center (2010–2022). Clinical characteristics, including biochemical markers and BMD, were investigated. HBS was defined as profound hypocalcemia of less than 8.4 mg/dL (2.1 mmol/L) or prolonged hypocalcemia for more than 4 days after PTX.
Results:
A total of 91 patients were included: 18 (19.8%) with SHPT and 73 (80.2%) with THPT. Subtotal PTX was performed in 80 patients (87.9%), while 11 patients (12.1%) underwent total PTX with autotransplantation (TPTX + AT). HBS occurred in 31 patients (34.1%), with a higher incidence in patients with SHPT (72.2%) and all patients who underwent TPTX + AT.Patients with HBS required more calcium supplementation and had higher ALP levels at all timepoints (P < 0.001). In the HBS group, BMD improved more significantly in the femur (P = 0.005) and showed a trend towards improvement in the spine (P = 0.059). Risk factors for HBS included younger age, SHPT, and elevated preoperative ALP and intact parathyroid hormone levels.
Conclusion
HBS is characterized by severe hypocalcemia due to calcium reabsorption into bone after PTX. Identifying risk factors for HBS may promote early risk stratification and tailored perioperative management, including surgical approach, especially for high-risk patients.
5.Validating the Korean Geriatric Assessment Tool in Elderly Multiple Myeloma Patients: A Multicenter Study
Ji Yun LEE ; Sang-A KIM ; Youngil KOH ; Ho-Young YHIM ; Gyeong-Won LEE ; Chang-Ki MIN ; Young Rok DO ; Hyo Jung KIM ; Sung Hwa BAE ; Hyeon-Seok EOM ; Sung-Hoon JUNG ; Hyunkyung PARK ; Seung-Hyun NAM ; Ji Hyun LEE ; Sung-Hyun KIM ; Hyun Jung LEE ; Young Seob PARK ; Soo-Mee BANG
Cancer Research and Treatment 2026;58(1):311-319
Purpose:
This study evaluates the Korean Cancer Study Group Geriatric Score-7 (KG-7) frailty screening tool’s effectiveness in elderly multiple myeloma (MM) patients to prevent under and overtreatment.
Materials and Methods:
This prospective pilot cohort study included 100 elderly patients aged 70 and older with newly diagnosed MM who had not undergone transplantation from August 2020 to January 2022.
Results:
The median age was 77 years, and 73.0% of patients were classified at International Staging System stages 2 or 3. Using a 5-point cutoff on the KG-7 index (non-frail, score ≥ 5; frail, score < 5), 31% were categorized as frail. After a median follow-up of 26.8 months, the 3-year overall survival rate was 73.0%. There was no statistically significant association between any frailty index and the risk of death. However, frail patients defined by the simplified frailty index (hazard ratio [HR], 2.49; 95% confidence interval [CI], 1.09 to 5.95; p=0.030) and by KG-7 (HR, 2.43; 95% CI, 1.03 to 5.86; p=0.043) had a significantly higher risk of grade 3-4 non-hematologic toxicity, whereas the International Myeloma Working Group definition did not. Over a 24-month tracking period, vulnerability as measured by KG-7 either improved or deteriorated.
Conclusion
The pilot study, which had a limited number of participants, did not demonstrate KG-7’s effectiveness in predicting survival; however, it successfully predicted severe non-hematologic toxicities. We plan to conduct larger studies in elderly MM patients to determine whether KG-7 can help tailor their treatment regimens.
6.Cost-Effectiveness Analysis of Daratumumab Monotherapy and Subsequent Therapies in Heavily Treated Relapsed/Refractory Multiple Myeloma: A Feasible Methodology using a Korean Nationwide Population Cohort
Sung-Soo PARK ; Suein CHOI ; Seungpil JUNG ; Seunghoon HAN ; Chaehyeon LEE ; Jinseon HAN ; Soyoung KIM ; Kihyun KIM ; Chang-Ki MIN
Cancer Research and Treatment 2026;58(1):300-310
Purpose:
High-cost novel therapies for multiple myeloma (MM) require evaluation of efficacy and cost-effectiveness.
Materials and Methods:
This study developed a methodology to assess cost-effectiveness using nationwide data from 11,450 newly diagnosed MM patients. A novel algorithm was applied to identify lines of therapy (LoT).
Results:
The number of newly diagnosed MM patients increased significantly, from 873 in 2010 to 1,464 in 2019 (p < 0.001). Advancing LoT was associated with shorter time to next treatment (TTNT) and overall survival (OS) (p < 0.001), while all-cause medical costs increased with each LoT (p < 0.001). Bortezomib-melphalan-prednisolone was the most common frontline regimen for transplant-ineligible patients (29.2%), while bortezomib-thalidomide-dexamethasone was most used for transplant-eligible patients (11.3%). Daratumumab monotherapy demonstrated superior second TTNT (7.8 vs. 5.2 months) and OS (8.5 vs. 5.3 months) compared to standard care in heavily treated MM patients, with statistical significance maintained after cost adjustment. For subsequent therapies following daratumumab, a methodology was developed to estimate required medical costs using the incremental cost-effectiveness ratio (ICER): Expected cost ($)=ICER×(Expected life expectancy–0.567)+35,601.
Conclusion
This study provides a novel cost-effectiveness framework linking treatment efficacy and real-world costs, supporting predictions of societal costs for future MM therapies.
7.Effects of Intraoral Vibration Stimulation on Brain Activity and Cognitive Function in Older Adults:A Pilot Study
Na-Hee CHANG ; Keun-Suh KIM ; Ji Won HAN ; Won-Seok KIM ; Ki Woong KIM ; Hyo-Jung LEE
Journal of Korean Dental Science 2026;19(1):10-22
Purpose:
Declines in masticatory function have been reported to be closely associated with cognitive impairment and reduced brain activity in older adults. This study aimed to investigate the effects of intraoral vibratory stimulation on masticatory function, cognitive performance, and brain activity in elderly individuals and to evaluate its potential efficacy.
Materials and Methods:
Participants were divided into a vibration-stimulation group (n=9) and a non-vibration control group (n=7). Baseline assessments were conducted at the first visit. Participants then received either vibratory stimulation or a wash-out (control) condition for two weeks, followed by the same assessments at the final visit. Evaluation measures were dental assessments (maximum bite force, masticatory performance, and salivary flow rate), cognitive tests (CANTAB, paper-based and computerized tests), quantitative electroencephalography (qEEG), and functional magnetic resonance imaging (fMRI) during a short-term memory task.
Results:
No significant long-term effects or statistically meaningful differences were observed between the two groups in cognitive performance or brain activity. Similarly, no pre- to post-intervention differences were found between groups in dental measures related to masticatory function (maximum bite force, masticatory performance, and salivary flow rate). Due to the limited sample size, this study functioned as a pilot study focusing on descriptive rather than inferential statistical analysis.
Conclusion
Intraoral vibratory stimulation did not demonstrate immediate or clear effects on cognitive function or brain activity in older adults, suggesting the need for optimization of stimulation parameters such as location and intensity. Future studies with larger sample sizes and improved stimulation methods replicating masticatory function are warranted to further explore the potential cognitive benefits.
9.Clinical Characteristics and Visual Prognostic Biomarkers in Pericentral Retinitis Pigmentosa: A Study in a South Korean Cohort
Su Ho BAE ; Seung Woo CHOI ; Chang Ki YOON ; Un Chul PARK ; Kyu Hyung PARK ; Eun Kyoung LEE
Korean Journal of Ophthalmology 2025;39(2):157-169
Purpose:
To investigate the clinical characteristics of South Korean patients with pericentral retinitis pigmentosa (RP) and to identify clinical biomarkers associated with rapid visual acuity decline based on baseline factors.
Methods:
This retrospective study included 59 eyes of 31 patients diagnosed with pericentral RP. Comprehensive ophthalmological examinations and genetic sequencing were conducted to assess the baseline characteristics. For biomarker analysis, eyes were categorized into two groups based on the annual rate of change in visual acuity. The clinical findings of the two groups were evaluated to identify the biomarkers associated with rapid loss of visual acuity.
Results:
Patients with pericentral RP in this study exhibited a mean best-corrected visual acuity of 0.17 ± 0.23 in logarithm of the minimum angle of resolution. The visual field test showed annular or semicircular scotoma with relatively preserved periphery and 27 eyes (45.8%) exhibited no macular complications in optical coherence tomography. Genetic analysis identified genes associated with previous typical and pericentral RP studies but also highlighted that many genetic causes of pericentral RP remain unidentified. Of the 55 eyes for which the rate of visual acuity change could be estimated, 18 exhibited an annual decline of ≥10%, whereas 37 showed an annual decline of <10%. Male sex and prolonged b-wave latency on dark-adapted 0.01 electroretinogram correlated with rapid visual acuity decline in the multivariate analysis.
Conclusions
South Korean patients with pericentral RP exhibited a milder phenotype compared to typical RP patients reported in previous studies. Genetic analysis revealed heterogeneity, with mutations in some genes commonly associated with milder forms of RP. Male sex and prolonged b-wave latency on dark-adapted 0.01 electroretinogram were significant biomarkers for predicting rapid visual acuity decline. Monitoring initial b-wave latency is important for predicting visual decline, particularly in male patients with pericentral RP.
10.Explainable paroxysmal atrial fibrillation diagnosis using an artificial intelligence-enabled electrocardiogram
Yeongbong JIN ; Bonggyun KO ; Woojin CHANG ; Kang-Ho CHOI ; Ki Hong LEE
The Korean Journal of Internal Medicine 2025;40(2):251-261
Background/Aims:
Atrial fibrillation (AF) significantly contributes to global morbidity and mortality. Paroxysmal atrial fibrillation (PAF) is particularly common among patients with cryptogenic strokes or transient ischemic attacks and has a silent nature. This study aims to develop reliable artificial intelligence (AI) algorithms to detect early signs of AF in patients with normal sinus rhythm (NSR) using a 12-lead electrocardiogram (ECG).
Methods:
Between 2013 and 2020, 552,372 ECG traces from 318,321 patients were collected and split into training (n = 331,422), validation (n = 110,475), and test sets (n = 110,475). Deep neural networks were then trained to predict AF onset within one month of NSR. Model performance was evaluated using the area under the receiver operating characteristic curve (AUROC). An explainable AI technique was employed to identify the inference evidence underlying the predictions of deep learning models.
Results:
The AUROC for early diagnosis of PAF was 0.905 ± 0.007. The findings reveal that the vicinity of the T wave, including the ST segment and S-peak, significantly influences the ability of the trained neural network to diagnose PAF. Additionally, comparing the summarized ECG in NSR with those in PAF revealed that nonspecific ST-T abnormalities and inverted T waves were associated with PAF.
Conclusions
Deep learning can predict AF onset from NSR while detecting key features that influence decisions. This suggests that identifying undetected AF may serve as a predictive tool for PAF screening, offering valuable insights into cardiac dysfunction and stroke risk.

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