1.Regions of Homozygosity Identified with a Chromosomal Microarray in a Korean Population:Distribution, Frequency, and Clinical Interpretation
Jaeryuk KIM ; Sunghee MIN ; Chang Ahn SEOL ; Eul-Ju SEO
Annals of Laboratory Medicine 2026;46(1):83-93
Background:
Single nucleotide polymorphism-based chromosomal microarray analysis (CMA) can detect regions of homozygosity (ROHs), which may be associated with medical conditions; however, limited ROH data, especially in East Asians, complicates clinical interpretations. We characterized ROH distributions and frequencies in a Korean population using CMA, highlighting clinically relevant findings, including suspected uniparental disomy (UPD), using standardized criteria.
Methods:
We analyzed ROHs in 1,731 individuals who underwent postnatal CMA at a Ko-rean medical center. ROHs ≥ 3 Mb long were detected using the CytoScan Dx platform and Chromosome Analysis Suite Dx. Suspected UPD and consanguinity were assessed per the American College of Medical Genetics and Genomics technical standards.
Results:
We identified 3,962 ROHs, with 76.7% of patients carrying at least one. Common “hotspot” regions included 3p21.31p21.1 (20.3%), 11p11.2 (18.2%), 1q21.1q21.3(17.7%), and 1p33p32.3 (12.0%). Almost all ROHs observed in > 1% of patients had a median size of < 5 Mb. ROH frequencies correlated negatively with chromosomal recombina-tion rates and positively with gene densities. Additionally, 1.2% (N = 21) of patients exhib-ited ROH patterns suggestive of UPD or consanguinity (13 suspected UPDs on imprinted chromosomes, 6 on non-imprinted chromosomes, and 2 consanguinities); 8 of 13 patients with suspected UPD were diagnosed as having imprinting disorders, with no pathogenic copy number variations detected.
Conclusions
Our population-specific ROH data for Koreans improve clinical interpretations by minimizing the risk of overinterpreting benign variants and highlight the value of standardized criteria for reliably detecting UPD and consanguinity and integrating ROH analysis into routine CMA interpretations.
3.Impact of Thyroid CT on Detecting Macroscopic Nodal Metastasis in Patients With Papillary Thyroid Microcarcinoma
Young Hun JEON ; Ji Ye LEE ; Taehyuk HAM ; Kyu Sung CHOI ; Inpyeong HWANG ; Roh-Eul YOO ; Koung Mi KANG ; Ji-hoon KIM
Korean Journal of Radiology 2026;27(5):484-494
Objective:
To evaluate the impact of adding CT to ultrasound (US) for nodal assessment in patients with papillary thyroid microcarcinoma (PTMC), particularly in those with US-node-negative disease.
Materials and Methods:
This single-center retrospective study included consecutive patients with PTMC (≤1 cm on US) who underwent both US and CT for PTMC staging between August 2016 and January 2020, and subsequently underwent surgery including neck dissection. The number of patients with clinical N1 and pathological N1 disease was assessed. The diagnostic performance of US, CT, and combined US + CT (positive if either was positive) for macroscopic lymph node metastasis (LNM) (i.e., metastatic tumor foci >2 mm) was evaluated. Cases with discordant nodal staging between US and CT were identified.The diagnostic utility of CT was also assessed in a subgroup of patients with node-negative findings on US.
Results:
Among 982 patients (mean age ± standard deviation, 47.3 ± 11.5 years; 774 female), pathological analysis confirmed cervical LNM in 377 patients, including macroscopic, microscopic, and size-unknown LNM in 187, 175, and 15 patients, respectively. The addition of CT to US improved sensitivity for detecting macroscopic LNM compared to US alone (68.4% [128/187] vs. 26.7% [50/187]; P < 0.001), while maintaining high specificity despite a significant decrease (90.9% [709/780] vs. 97.2% [758/780]; P < 0.001). Discordant nodal staging between US and CT regarding macroscopic LNM was observed in 149 cases (15.2% [149/982]), with 131 patients (87.9% [131/149]) being upstaged by CT. In patients with node-negative US findings, CT detected US-undetected macroscopic LNM in 78 patients (8.7% [78/895]) and exhibited a sensitivity of 56.9% (78/137) and specificity of 93.5% (709/758) for macroscopic LNM.
Conclusion
The integration of CT with US improved sensitivity for detecting macroscopic LNM in patients with PTMC, identifying those who would otherwise be inappropriately considered candidates for active surveillance based solely on US findings. This may assist in refining patient management.
4.Long-term Immunogenicity of the 13-valent Pneumococcal Conjugate Vaccine during Adjuvant Chemotherapy in Patients with Gastric and Colorectal Cancer: A 5-Year Follow-up of a Randomized Controlled Trial
Hyeon-Jong KIM ; Hyunjin BANG ; Hyun-Jung SHIM ; Jun Eul HWANG ; Sang-Hee CHO ; Ik-Joo CHUNG ; Seung Ji KANG ; Jong Gwang KIM ; Seung-Hoon BEOM ; A-Yeung JANG ; Joon Young SONG ; Woo Kyun BAE
Cancer Research and Treatment 2026;58(1):61-70
Purpose:
Current guidelines recommend vaccination at least 2 weeks before chemotherapy initiation to optimize the immune response despite limited evidence. Our previous study indicated no differences in short-term immune response for the 13-valent pneumococcal conjugate vaccine (PCV13) according to the vaccination timing. This study aims to investigate the long-term efficacy of PCV13 and clinical factors associated with the respective antibody response.
Materials and Methods:
Patients with gastric or colorectal cancer who received adjuvant chemotherapy were enrolled and divided into two groups: vaccinated 2 weeks before chemotherapy (arm A) and vaccinated concurrently with chemotherapy (arm B). Serum samples were collected before vaccination and in one month, 3 years, and 5 years. Immune responses were measured using enzyme-linked immunosorbent assay and multiplex opsonophagocytosis assay.
Results:
Including 63 patients, both groups showed an initial increase in the geometric mean titers of opsonophagocytic activity and the geometric mean concentrations of serotype-specific IgG levels after one month, followed by a decline at 3 and 5 years, particularly for serotypes 1, 14, 18C, and 19A. Despite the decline, global protection was maintained for 5 years, although global response decreased. The two arms did not show significant differences in immunogenicity nor in factors such as vaccination timing, age, cancer type, or chemotherapy regimen.
Conclusion
Vaccination timing is not a significant factor for the immunogenicity of PCV13 in cancer patients undergoing adjuvant chemotherapy. Global protection against pneumococcal infection was sustained for > 5 years, and global response remained in over half of patients.
5.Study of the characteristics of cardiac arrest in Chungcheongnam-do
Yong Oh KIM ; Il Kug CHOI ; Eul Hee ROH ; Han Joo CHOI
Journal of the Korean Society of Emergency Medicine 2026;37(2):95-103
Objective:
This study examined the characteristics of cardiac arrest in Chungcheongnam-do, categorized by cause and region.
Methods:
Open survey indicators and institutional research data were used, and raw datasets were analyzed. Cardiac arrest cases were categorized into traumatic and nontraumatic groups and compared according to the city type. The annual trends in each variable were also evaluated.
Results:
From 2009 to 2019, the incidence of cardiac arrest in Chungcheongnam-do remained consistently higher than the national average. The standardized incidence of nontraumatic cardiac arrest showed no significant differences according to the city type. In contrast, the standardized incidence of traumatic cardiac arrest was higher than the national average and consistently greater in counties than in cities or the Cheonan-Asan group. Traffic fatalities were also highest in counties and lowest in Cheonan-Asan.
Conclusion
The elevated cardiac arrest mortality rate in Chungcheongnam-do was largely attributable to trauma, with traffic accidents representing the leading cause, particularly in rural areas. These findings may serve as a basis for identifying the regional characteristics of cardiac arrest and for developing strategies to reduce mortality in Chungcheongnam-do.
6.Constitutional Chromosome 21 Abnormality in B-ALL with iAMP21 in a Patient Developing Treatment-Related Myelodysplastic Syndrome
Inhwa KIM ; Su Hyun YOON ; Sunghan KANG ; Kyung-Nam KOH ; Mi Young KIM ; Young-Uk CHO ; Sang-Hyun HWANG ; Seongsoo JANG ; Eul-Ju SEO ; Beom Hee LEE ; Sunghee MIN ; Hyunwoo BAE ; Ho Joon IM ; Hyery KIM
Clinical Pediatric Hematology-Oncology 2025;32(1):23-28
The initial molecular cytogenetic characteristics of blasts plays a significant role in determining the treatment course of B-cell acute lymphoblastic leukemia (B-ALL).B-ALL with intrachromosomal amplification of chromosome 21 (iAMP21) has been well known to have unfavorable prognosis. Also, there are previously recognized germline mutations that increase the risk of ALL, such as trisomy 21, Down syndrome. This case report is about a 16-year-old girl who presented with lymphadenitis, purpura, and fever followed by initial lab of elevated white blood cell with blasts.She had some notable facial features, but no typical Down syndrome related one.Bone marrow biopsy and fluorescence in situ hybridization finalized the diagnosis as B-ALL with iAMP21, high-risk group. The minimal residual disease-negative complete remission was achieved after the induction chemotherapy with Korean multicenter high-risk protocol. However, abnormal karyotype was sustained in bone marrow. Microarrays with her buccal swab raised the possibility that the abnormal karyotype was not from the leukemic blasts but rather from the germline. Although she underwent scheduled chemotherapy uneventfully as slow early responder type, thrombocytopenia and abnormal karyotype persisted, leading to the diagnosis of acute myeloid leukemia. Additional chemotherapy and peripheral blood stem cell transplantation was performed which resulted in engraftment. This case highlights the discovery of a constitutional genetic aberration, which played like a silent yet critical background factor for B-ALL with iAMP21. As the number of reported cases are limited, the role of germline chromosome 21 mutation as the indicator for prognosis of B-ALL should be studied further.
7.Nipple swab culture profile as a potential predictor of postoperative complications in autologous breast reconstruction: a retrospective study
Sun-Hyeok KIM ; Yi-Jun MOON ; Seung-Pil JUNG ; Hyung-Chul LEE ; Jae-Ho CHUNG ; Eul-Sik YOON
Archives of Aesthetic Plastic Surgery 2025;31(2):35-40
Background:
The nipple is a potential source of pathogens because its lactiferous ducts act as direct conduits from the nipple–areolar complex to the breast parenchyma. Our previous studies identified breast microbiota as a factor in postoperative complications following immediate breast reconstruction using silicone implants and acellular dermal matrix. This study aimed to investigate the correlation between preoperative nipple swab microbiota and the incidence of surgical site infections (SSIs) after autologous breast reconstruction.
Methods:
We conducted a retrospective chart review of patients who underwent autologous breast reconstruction following total mastectomy. Preoperative nipple swab cultures were obtained. Patient demographics, surgical characteristics, and complication rates were compared between culture-positive and culture-negative groups. Microbiological data, including antibiotic‑resistance profiles, were collected.
Results:
Among 39 reconstructed breasts, 18 (46.9%) had positive preoperative nipple cultures. The mean duration of drain placement was significantly longer in the culture‑positive group (14.39±3.96 days) than in the culture‑negative group (12.14±2.76 days, P=0.045). Methicillin‑susceptible Staphylococcus epidermidis accounted for 55.0% of isolates. Of the four SSIs observed, three occurred in patients with positive preoperative cultures.
Conclusions
Although pathogen strains differed between preoperative and postoperative settings, obtaining preoperative nipple microflora cultures and determining antibiotic‑resistance profiles can guide immediate antibiotic selection for SSIs and enhance postoperative management.
8.Nipple swab culture profile as a potential predictor of postoperative complications in autologous breast reconstruction: a retrospective study
Sun-Hyeok KIM ; Yi-Jun MOON ; Seung-Pil JUNG ; Hyung-Chul LEE ; Jae-Ho CHUNG ; Eul-Sik YOON
Archives of Aesthetic Plastic Surgery 2025;31(2):35-40
Background:
The nipple is a potential source of pathogens because its lactiferous ducts act as direct conduits from the nipple–areolar complex to the breast parenchyma. Our previous studies identified breast microbiota as a factor in postoperative complications following immediate breast reconstruction using silicone implants and acellular dermal matrix. This study aimed to investigate the correlation between preoperative nipple swab microbiota and the incidence of surgical site infections (SSIs) after autologous breast reconstruction.
Methods:
We conducted a retrospective chart review of patients who underwent autologous breast reconstruction following total mastectomy. Preoperative nipple swab cultures were obtained. Patient demographics, surgical characteristics, and complication rates were compared between culture-positive and culture-negative groups. Microbiological data, including antibiotic‑resistance profiles, were collected.
Results:
Among 39 reconstructed breasts, 18 (46.9%) had positive preoperative nipple cultures. The mean duration of drain placement was significantly longer in the culture‑positive group (14.39±3.96 days) than in the culture‑negative group (12.14±2.76 days, P=0.045). Methicillin‑susceptible Staphylococcus epidermidis accounted for 55.0% of isolates. Of the four SSIs observed, three occurred in patients with positive preoperative cultures.
Conclusions
Although pathogen strains differed between preoperative and postoperative settings, obtaining preoperative nipple microflora cultures and determining antibiotic‑resistance profiles can guide immediate antibiotic selection for SSIs and enhance postoperative management.
9.Constitutional Chromosome 21 Abnormality in B-ALL with iAMP21 in a Patient Developing Treatment-Related Myelodysplastic Syndrome
Inhwa KIM ; Su Hyun YOON ; Sunghan KANG ; Kyung-Nam KOH ; Mi Young KIM ; Young-Uk CHO ; Sang-Hyun HWANG ; Seongsoo JANG ; Eul-Ju SEO ; Beom Hee LEE ; Sunghee MIN ; Hyunwoo BAE ; Ho Joon IM ; Hyery KIM
Clinical Pediatric Hematology-Oncology 2025;32(1):23-28
The initial molecular cytogenetic characteristics of blasts plays a significant role in determining the treatment course of B-cell acute lymphoblastic leukemia (B-ALL).B-ALL with intrachromosomal amplification of chromosome 21 (iAMP21) has been well known to have unfavorable prognosis. Also, there are previously recognized germline mutations that increase the risk of ALL, such as trisomy 21, Down syndrome. This case report is about a 16-year-old girl who presented with lymphadenitis, purpura, and fever followed by initial lab of elevated white blood cell with blasts.She had some notable facial features, but no typical Down syndrome related one.Bone marrow biopsy and fluorescence in situ hybridization finalized the diagnosis as B-ALL with iAMP21, high-risk group. The minimal residual disease-negative complete remission was achieved after the induction chemotherapy with Korean multicenter high-risk protocol. However, abnormal karyotype was sustained in bone marrow. Microarrays with her buccal swab raised the possibility that the abnormal karyotype was not from the leukemic blasts but rather from the germline. Although she underwent scheduled chemotherapy uneventfully as slow early responder type, thrombocytopenia and abnormal karyotype persisted, leading to the diagnosis of acute myeloid leukemia. Additional chemotherapy and peripheral blood stem cell transplantation was performed which resulted in engraftment. This case highlights the discovery of a constitutional genetic aberration, which played like a silent yet critical background factor for B-ALL with iAMP21. As the number of reported cases are limited, the role of germline chromosome 21 mutation as the indicator for prognosis of B-ALL should be studied further.
10.Factors Influencing Cone Contrast Sensitivity in Koreans Aged 60 Years and Older
Han Eul LEE ; Hee Seung CHIN ; Na Rae KIM ; Ji Won JUNG
Journal of the Korean Ophthalmological Society 2025;66(1):55-62
Purpose:
To examine the factors impacting cone contrast sensitivity in Koreans aged > 60 years who are scheduled for cataract surgery and do not have congenital color vision deficiencies.
Methods:
The ColorDx Cone contrast test HD® (CCT-HD; Konan Medical, Inc., CA, USA) was administered to 33 Korean individuals (33 eyes) to evaluate CCT scores before and after cataract surgery, as well as changes in CCT scores according to the degree of progression by cataract type. Correlations between CCT scores and age, best corrected visual acuity (BCVA), regional retinal thickness, and length of the photoreceptor outer segment (PROS) at the fovea were analyzed in pseudophakic eyes.
Results:
Average scores for short-, medium-, and long-wavelength cone contrast sensitivity tests (S-CCT, M-CCT, and L-CCT, respectively) improved after surgery (p = 0.010, p = 0.001, and p = 0.028, respectively). Comparing CCT score changes before and after surgery by cataract progression, higher cataract grades were associated with greater CCT score changes, though the differences were not statistically significant (p > 0.05). In pseudophakic eyes, S-CCT scores negatively correlated with age (p = 0.017). No significant correlations were found between S-CCT, M-CCT, and L-CCT scores and BCVA, whereas S-CCT, M-CCT, and L-CCT scores positively correlated with PROS at the fovea (p < 0.001).
Conclusions
Cone contrast sensitivity in individuals aged > 60 years is influenced by age and cataract status and may serve as a valuable indicator of visual function in clinical research.

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