Twenty-Five Year Trend Change in the Etiology of Pediatric Invasive Bacterial Infections in Korea, 1996–2020

Background@#The coronavirus disease-2019 (COVID-19) pandemic has contributed to the change in the epidemiology of many infectious diseases. This study aimed to establish the pre-pandemic epidemiology of pediatric invasive bacterial infection (IBI). @*Methods@#A retrospective multicenter-based surveillance for pediatric IBIs has been maintained from 1996 to 2020 in Korea. IBIs caused by eight bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella species) in immunocompetent children > 3 months of age were collected at 29 centers. The annual trend in the proportion of IBIs by each pathogen was analyzed. @*Results@#A total of 2,195 episodes were identified during the 25-year period between 1996 and 2020. S. pneumoniae (42.4%), S. aureus (22.1%), and Salmonella species (21.0%) were common in children 3 to 59 months of age. In children ≥ 5 years of age, S. aureus (58.1%), followed by Salmonella species (14.8%) and S. pneumoniae (12.2%) were common. Excluding the year 2020, there was a trend toward a decrease in the relative proportions of S. pneumoniae (rs = −0.430, P = 0.036), H. influenzae (rs = −0.922, P 3 months of age. These findings can be used as the baseline data to navigate the trend in the epidemiology of pediatric IBI in the post COVID-19 era.

Primary Subcapsular Reflux as an Etiology of Subcapsular Renal Abscess

Herein, we report two rare cases of renal infection. The first case was renal subcapsular urine reflux in a 8-month-old girl with recurrent urinary tract infection and the second was subcapsular abscess in a 14-year-old girl with diabetes, who was successfully treated with percutaneous drainage. It has been suggested that renal subcapsular abscesses could be caused by the direct reflux of urine into the subcapsular space, rather than spread of infection from an existing parenchymal lesion, and that complete recovery can be achieved if percutaneous drainage is performed in a timely manner. We propose primary subcapsular reflux, in which urine directly refluxes upwards into the subcapsular space of the kidney, as one of the mechanisms for development of renal subcapsular abscesses.

A Case of Brain Abscess due to Parvimonas micra in a Healthy Child without Dental Disease

Parvimonas micra is a non-spore-forming anaerobic gram-positive coccus and a known commensal of the skin, gums, vagina, and gastrointestinal tract. It is rarely associated with severe infections, which typically follow invasive procedures such as dental treatment. We describe a case of a brain abscess caused by P. micra in an immunocompetent 11-year-old boy without periodontal disease. He presented with a 7-day history of headaches and vomiting, and complained of diplopia that began on the day of presentation. He did not have any recent dental treatment or specific past medical history. A brain abscess in the left frontoparietal lobe was noted on brain magnetic resonance imaging. P. micra was cultured from brain abscess aspirate. He was successfully treated with surgical drainage and combined antibiotic therapy with ceftriaxone and metronidazole for 6 weeks.

Atypical Presentation of Chronic Granulomatous Disease in a Neonate with a Pulmonary Granuloma Mimicking a Tumor: A Case Report

Chronic granulomatous disease (CGD) is an uncommon primary immune deficiency caused by phagocytes defective in oxygen metabolite production. It results in recurrent bacterial or fungal infections. Herein, we present a case of CGD with a large pulmonary granuloma in a neonate and review the imaging findings. The patient was a 24-day-old neonate admitted to the hospital with fever. A round opacified lesion was identified on the chest radiograph. Subsequent CT and MRI revealed a round mass with heterogeneous enhancement in the right lower lobe. There were foci of diffusion restriction in the mass. Surgical biopsy of the mass revealed chronic granuloma. Finally, the neonate was diagnosed with CGD caused by mutation of the gp91phox gene. Herein, we present the clinical and imaging findings of this unusual case of CGD.

The First Reported Case of Infant Botulism in Korea: Treatable Infantile Neuromuscular Disease

Botulism is a rare neuromuscular disorder caused by neurotoxins produced by Clostridium botulinum. The diagnosis of infant botulism may be obscured or delayed, as its presentation is similar to that of infantile neuromuscular disorders. We report the first Korean case of infant botulism in an acute progressive floppy infant with poor sucking and a weak cry. No abnormalities were found in all blood, cerebrospinal fluid, genetic test, nerve conduction study, and imaging studies. A stool-toxin test was finally performed under suspicion of infant botulism, and the result was positive. The patient was immediately treated with heptavalent botulism antitoxin. Follow-up after 3 months showed normal development with a complete resolution of all symptoms. Therefore, clinical suspicion of infant botulism, which is a treatable infantile neuromuscular disease, is essential for early diagnosis and prompt treatment in the differential diagnosis of a floppy infant.

The First Reported Case of Infant Botulism in Korea: Treatable Infantile Neuromuscular Disease

Botulism is a rare neuromuscular disorder caused by neurotoxins produced by Clostridium botulinum. The diagnosis of infant botulism may be obscured or delayed, as its presentation is similar to that of infantile neuromuscular disorders. We report the first Korean case of infant botulism in an acute progressive floppy infant with poor sucking and a weak cry. No abnormalities were found in all blood, cerebrospinal fluid, genetic test, nerve conduction study, and imaging studies. A stool-toxin test was finally performed under suspicion of infant botulism, and the result was positive. The patient was immediately treated with heptavalent botulism antitoxin. Follow-up after 3 months showed normal development with a complete resolution of all symptoms. Therefore, clinical suspicion of infant botulism, which is a treatable infantile neuromuscular disease, is essential for early diagnosis and prompt treatment in the differential diagnosis of a floppy infant.

A Case of Recurrent Rosai-Dorfman Disease Successfully Treated with 2-Chlorodeoxyadenosine (Cladribine) / 임상소아혈액종양

Sinus histiocytosis with massive lymphadenopathy, also known as Rosai-Dorfman disease (RDD), is a rare histiocytic disorder of unknown etiology. Most patients with RDD have spontaneous remission, but in some patients, the disease recurs after complete remission and may not respond to general treatment. Some patients with RDD involving the extranodal system can have serious symptoms such as vital organ dysfunction due to mass effects, neurological symptoms caused by intracranial involvement, and respiratory distress with airway involvement. We report the case of a 7-year-old girl with severe dyspnea due to refractory extranodal RDD that caused progressive upper airway obstruction. She was admitted because of nasal congestion and persistent cervical lymphadenopathy, and diagnosed as having RDD by cervical lymph node incisional biopsy. The initial prednisone treatment did not improve her symptoms. The following contrast-enhanced neck computed tomography revealed a newly developed airway mass protruding in the upper trachea. After 8 weeks of chemotherapy with vinblastine, methotrexate, and prednisone, complete remission was attained. Seven months after chemotherapy cessation, the disease recurred, and chemotherapy with vincristine, cytarabine, and prednisone was resumed. Despite the chemotherapy and emergency radiotherapy, no improvement was observed in the cervical lymph node enlargement and airway obstructive symptom due to the upper tracheal mass. 2-Chlorodeoxyadenosine (cladribine) therapy was initiated, and the patient got complete remission after 6 cycles of the cladribine treatment and maintained no evidence of disease for 2 years. We suggest that cladribine is an effective treatment option for recurrent/refractory RDD.

An Epidemiologic Study on Hosts and Pathogens of Urinary Tract Infection in Urban Children of Korea (2012–2017)

PURPOSE: We aimed to determine characteristics of host, causative organisms, and antibiotic susceptibility of bacteria in pediatric patients with UTI living in metropolitan area of Korea. METHODS: Retrospective investigation was done for the causative organisms of UTI in 683 pediatric cases treated at Ajou University Hospital from 2012 to 2017. Patients were classified into Escherichia coli and non-E.coli group, where E.coli group was subdivided into ESBL(+) and ESBL(−) groups based on whether the bacteria could produce extended spectrum beta-lactamase (ESBL). Antibiotic susceptibility of the causative organism was also determined. RESULTS: A total of 683 UTIs occurred in 550 patients, of which 463 (67.8%) were first-time infection and 87 (32.2%) were recurrent ones (2–7 recurrences, 2.52 average), and 64.9% were male and 35.1% were female. The most common causative organism was E.coli (77.2%) and ESBL(+) E.coli was found in 126 cases. The susceptibility of E.coli to 3rd or 4th generation cephalosporin was relatively higher than that to ampicillin or amoxicillin/clavulanic acid. ESBL(+) E.coli showed higher resistance rate to 3rd or 4th generation cephalosporin than ESBL(−) E.coli . CONCLUSION: New treatment guideline should be considered due to the incidence of ESBL(+) E.coli increased up to one quarter of UTI cases.

Workplace violence experienced by emergency department workers and its association with stress and depression assessment

OBJECTIVE: This study examined the incidence of workplace violence (WPV) in an emergency department (ED), and its influence on ED workers' mental health. METHODS: A cross-sectional, anonymous survey was conducted on ED workers employed in a local emergency medical center during August 2018. The survey respondents' data on the demographic characteristics, WPV episode, Korean-translated Brief Encounter Psychosocial Instrument (BEPSI-K), stress questionnaire for Korean National Health and Nutrition Examination Survey (KNHANES), and Patient Health Questionnaire-9 (PHQ-9) were obtained. The results of the stress (BEPSI-K, KNHANES) and depression (PHQ-9) score were compared with the WPV experience of ED workers. RESULTS: A total of 104 of 120 ED workers (86.7%) were exposed to WPV. ED workers that experienced physical violence within the past year had higher KNHANES, BEPSI-K, and PHQ-9 than the workers, who did not experience such violence (P≤0.001). In addition, this survey demonstrated that a physical violence episode within the past year was associated with above moderate depression (P≤0.001; odds ratio, 19.597). CONCLUSION: Recent physical violence can cause psychiatric disorders in ED workers, such as depression or stress disorder. Therefore, policies are needed to prevent WPV in ED and support ED workers who have experienced WPV.

A Study of Central Diabetes Insipidus in Head and Neck Langerhans Cell Histiocytosis: A Single Center Experience / 임상소아혈액종양

BACKGROUND: Langerhans cell histiocytosis (LCH) frequently involves the head and neck and increases the risk of central nervous system (CNS) involvement of LCH, such as central diabetes insipidus (CDI), when the craniofacial bones are involved. We analyzed risk factors and clinical features of CDI among patients with LCH involving the head and neck. METHODS: From January 1, 2000 to May 1, 2018, 63 patients with histologically confirmed LCH in the Department of Pediatrics, Ajou University Hospital were retrospectively analyzed. RESULTS: Forty eight cases (76.2%) of patients had head and neck involvement, and 9 cases (14.3%) in craniofacial bones at the time of initial diagnosis of LCH. CDI was found in 6 cases (9.5%) among all LCH patients, 6 cases (12.2%) among patients with head and neck involvement, and 3 cases (33.3%) among patients with craniofacial bone involvement. Three cases of CDI occurred at the time of initial LCH diagnosis, and another 3 cases occurred at the time of 2, 4, and 8 years after initial LCH diagnosis. Of the 6 CDI patients, 3 had CNS risk lesions and 3 had no CNS risk lesions, but all had multi-system involvement of LCH. CONCLUSION: CDI can occur even in patients with head and neck LCH without CNS risk lesions, if there are multisystem involvement of LCH. Patients with head and neck LCH may develop CDI over time, so continuous observations should be done while considering the occurrence of CDI.

Clinical Characteristics of Severe Neutropenia in Children / 임상소아혈액종양

BACKGROUND: Severe neutropenia is defined as an absolute neutrophil count (ANC) less than 0.5×109/L, which is known to increase the risk of serious bacterial infections. The aim of this study was to investigate characteristics, etiology and differences between transient and chronic severe neutropenia in children.METHODS: 204 children, who were diagnosed with severe neutropenia at the Ajou University Hospital during a 5-year period, were included in the study. Clinical and laboratory features were analyzed. The patients were classified as having transient severe neutropenia (TSN) if recovery occurred within 6 months of diagnosis, and chronic severe neutropenia (CSN) if the neutropenia persisted for 6 months or more.RESULTS: 184 (90.2%) patients with TSN and 20 (9.8%) patients with CSN were identified. Most of the TSN occurred in patients less than 2 year of age (75.5%) and rarely occurred in patients 5 years or older (5.4%). The most common cause of TSN was infection-related neutropenia (82.6%), and most of the associated infections were respiratory infections (44.6%). Compared to TSN, CSN patients were younger at diagnosis (1.00 vs. 0.71, P < 0.001), had a lower ANC at diagnosis (364.8 vs. 214.9, P < 0.001), lower ANC at nadir (356.0 vs. 50.0, P < 0.001), and higher platelet count (188×10⁹ vs. 308×10⁹, P < 0.001), monocyte count (491.5×10⁶ vs. 832.9×10⁶, P=0.010) and CRP (0.22 vs. 0.85, P=0.036).CONCLUSION: Most of the severe neutropenia occurred in children younger than 2 years of age, and virus infection was the most common cause of TSN.

Differences in Clinical Characteristics of Transient Myeloproliferative Disease and Leukemia in Down Syndrome: A Single University Hospital Study / 임상소아혈액종양

BACKGROUND: Children with Down syndrome (DS) have a 10- to 20-fold increased risk of developing leukemia. However, in some patients, leukemia does not become apparent despite significant number of blast cells in the peripheral blood. This condition is called Transient myeloproliferative disorder (TMD), and is a disease entity unique to DS newborns and defined as the morphologic detection of blasts in DS less than three months of age. The present study investigated whether there was a difference between leukemia and TMD, and determined prognostic and risk factors.METHODS: We collected blood samples from 317 patients of 433 DS confirmed patients. We found 18 patients who had blast cells in their peripheral blood.RESULTS: Twelve patients were positive for blasts during the neonate period, and only one patient progressed to leukemia. The other 11 patients were later diagnosed with TMD. Six more patients were later diagnosed with leukemia, therefore, 7 patients were diagnosed with leukemia in total. All patients diagnosed with leukemia had anemia at the time of diagnosis, which was not found in TMD patients. All leukemia patients developed their disease after three months of life. Acute Myeloid Leukemia (AML) patients had additional chromosome mutation to trisomy 21 when they were diagnosed.CONCLUSION: In patients with Down Syndrome, anemia at diagnosis and age of onset could be helpful in distinguishing TMD from acute leukemia. Cancerous mutations in the chromosomes of peripheral and marrow blast cells of Down syndrome patients may foreshadow acute leukemia.

Clinical Characteristics of Severe Neutropenia in Children / 임상소아혈액종양

BACKGROUND: Severe neutropenia is defined as an absolute neutrophil count (ANC) less than 0.5×109/L, which is known to increase the risk of serious bacterial infections. The aim of this study was to investigate characteristics, etiology and differences between transient and chronic severe neutropenia in children. METHODS: 204 children, who were diagnosed with severe neutropenia at the Ajou University Hospital during a 5-year period, were included in the study. Clinical and laboratory features were analyzed. The patients were classified as having transient severe neutropenia (TSN) if recovery occurred within 6 months of diagnosis, and chronic severe neutropenia (CSN) if the neutropenia persisted for 6 months or more. RESULTS: 184 (90.2%) patients with TSN and 20 (9.8%) patients with CSN were identified. Most of the TSN occurred in patients less than 2 year of age (75.5%) and rarely occurred in patients 5 years or older (5.4%). The most common cause of TSN was infection-related neutropenia (82.6%), and most of the associated infections were respiratory infections (44.6%). Compared to TSN, CSN patients were younger at diagnosis (1.00 vs. 0.71, P < 0.001), had a lower ANC at diagnosis (364.8 vs. 214.9, P < 0.001), lower ANC at nadir (356.0 vs. 50.0, P < 0.001), and higher platelet count (188×10⁹ vs. 308×10⁹, P < 0.001), monocyte count (491.5×10⁶ vs. 832.9×10⁶, P=0.010) and CRP (0.22 vs. 0.85, P=0.036). CONCLUSION: Most of the severe neutropenia occurred in children younger than 2 years of age, and virus infection was the most common cause of TSN.

Differences in Clinical Characteristics of Transient Myeloproliferative Disease and Leukemia in Down Syndrome: A Single University Hospital Study / 임상소아혈액종양

BACKGROUND: Children with Down syndrome (DS) have a 10- to 20-fold increased risk of developing leukemia. However, in some patients, leukemia does not become apparent despite significant number of blast cells in the peripheral blood. This condition is called Transient myeloproliferative disorder (TMD), and is a disease entity unique to DS newborns and defined as the morphologic detection of blasts in DS less than three months of age. The present study investigated whether there was a difference between leukemia and TMD, and determined prognostic and risk factors. METHODS: We collected blood samples from 317 patients of 433 DS confirmed patients. We found 18 patients who had blast cells in their peripheral blood. RESULTS: Twelve patients were positive for blasts during the neonate period, and only one patient progressed to leukemia. The other 11 patients were later diagnosed with TMD. Six more patients were later diagnosed with leukemia, therefore, 7 patients were diagnosed with leukemia in total. All patients diagnosed with leukemia had anemia at the time of diagnosis, which was not found in TMD patients. All leukemia patients developed their disease after three months of life. Acute Myeloid Leukemia (AML) patients had additional chromosome mutation to trisomy 21 when they were diagnosed. CONCLUSION: In patients with Down Syndrome, anemia at diagnosis and age of onset could be helpful in distinguishing TMD from acute leukemia. Cancerous mutations in the chromosomes of peripheral and marrow blast cells of Down syndrome patients may foreshadow acute leukemia.

Neonatal Hepatic Hemangioendothelioma: A Single Institute Experience / 임상소아혈액종양

BACKGROUND: Hepatic hemagioendothelioma in neonatal period was rarely seen, so standard treatment does not established yet.METHODS: A retrospective analysis of patients with neonatal hepatic hemangioendothelioma at Ajou University Hospital between 2001 and 2016 was performed.RESULTS: Six patients with hepatic hemangioendothelioma in neonatal period were founded. Mean age at diagnosis was 6.1 days (range, 1-26 days). Three patients have no symptoms; diagnostic approach was prenatal ultrasonography in 2 patients, and incidental abnormal ultrasonographic findings in 1 patient, but the other 3 patients have hepatomegaly and/or congestive heart failure. Three patients were observed without treatment and the other 3 patients received medical and/or surgical treatment. Three patients of those who did not receive treatment became spontaneous regression. Of the other 3 patients, 1 patient achieved complete tumor disappearance after surgical resection, another 1 patient achieved to decrease tumor size with interferon-alpha treatment for 6 months and then had complete resolution of tumor after partial liver lobectomy, and other 1 patient who received hepatic artery embolization decreased in the size and number of lesions and then regressed gradually.CONCLUSION: Asymptomatic patients with neonatal hepatic hemangioendothelioma could have spontaneous remission, but patients with symptoms such as hepatomegaly with congestive heart failure or thrombocytopenia needed to be applied with medical and/or surgical treatment.

Esthesioneuroblastoma in a boy with 47, XYY karyotype / 소아과

Neuroblastomas are sometimes associated with abnormal constitutional karyotypes, but the XYY karyotype has been rarely described in neuroblastomas. Here, we report a case of an esthesioneuroblastoma in a boy with a 47, XYY karyotype. A 6-year-old boy was admitted to our hospital because of nasal obstruction and palpable cervical lymph node, which he first noticed several days previously. A polypoid mass in the right nasal cavity was detected through sinuscopy. Biopsy of the right nasal polyp was performed. Based on the result, the patient was diagnosed with a high-grade esthesioneuroblastoma. Nuclear imaging revealed increased uptake in both the right posterior nasal cavity and the right cervical IB-II space, suggesting metastatic lymph nodes. Cytogenetic analysis revealed a 47, XYY karyotype. Twelve courses of concurrent chemotherapy were administered. Three years after the completion of chemotherapy, the patient had had no disease recurrence. He manifested behavioral violence and temper tantrums, so we started methylphenidate for correction of the behavior.

Neonatal Hepatic Hemangioendothelioma: A Single Institute Experience / 임상소아혈액종양

BACKGROUND: Hepatic hemagioendothelioma in neonatal period was rarely seen, so standard treatment does not established yet. METHODS: A retrospective analysis of patients with neonatal hepatic hemangioendothelioma at Ajou University Hospital between 2001 and 2016 was performed. RESULTS: Six patients with hepatic hemangioendothelioma in neonatal period were founded. Mean age at diagnosis was 6.1 days (range, 1-26 days). Three patients have no symptoms; diagnostic approach was prenatal ultrasonography in 2 patients, and incidental abnormal ultrasonographic findings in 1 patient, but the other 3 patients have hepatomegaly and/or congestive heart failure. Three patients were observed without treatment and the other 3 patients received medical and/or surgical treatment. Three patients of those who did not receive treatment became spontaneous regression. Of the other 3 patients, 1 patient achieved complete tumor disappearance after surgical resection, another 1 patient achieved to decrease tumor size with interferon-alpha treatment for 6 months and then had complete resolution of tumor after partial liver lobectomy, and other 1 patient who received hepatic artery embolization decreased in the size and number of lesions and then regressed gradually. CONCLUSION: Asymptomatic patients with neonatal hepatic hemangioendothelioma could have spontaneous remission, but patients with symptoms such as hepatomegaly with congestive heart failure or thrombocytopenia needed to be applied with medical and/or surgical treatment.

Human Parechovirus as an Important Cause of Central Nervous System Infection in Childhood

PURPOSE: Human parechovirus (HPeV) is an increasingly recognized pathogenic cause of central nervous system (CNS) infection in neonates. However, HPeV infections have not been studied in older children. This study determined the prevalence and clinical features of HPeV CNS infection in children in Korea. METHODS: Reverse transcription polymerase chain reaction assays were performed using HPeV-specific, 5′ untranslated, region-targeted primers to detect HPeV in cerebrospinal fluid (CSF) samples from children presenting with fever or neurologic symptoms from January 1, 2013, to July 31, 2014. HPeV genotyping was performed by sequencing the viral protein 3/1 region. Clinical and laboratory data were retrospectively abstracted from medical records and compared with those of enterovirus (EV)-positive patients from the same period. RESULTS: Of 102 CSF samples, six (5.9%) were positive for HPeV; two of 21 EV-positive samples were co-infected with HPeV. All samples were genotype HPeV3. Two HPeV-positive patients were <3 months of age and four others were over 1 year old. While HPeV-positive infants under 1 year of age presented with sepsis-like illness without definite neurologic abnormalities, HPeV-positive children over 1 year of age presented with fever and neurologic symptoms such as seizures, loss of consciousness, and gait disturbance. The CSF findings of HPeV-positive patients were mostly within the normal range, whereas most (73.7%) EV-positive patients had pleocytosis. CONCLUSIONS: Although HPeV is typically associated with disease in young infants, the results of this study suggest that HPeV is an emerging pathogen of CNS infection with neurologic symptoms in older childhood.

A Clinical Study on Hereditary Hemoglobinopathy: a Single Institute Experience / 임상소아혈액종양

BACKGROUND: Hemoglobinopathy is inherited anemia characterized by abnormal structure of one of the globin chains of the hemoglobin molecule and has been known to be rare in Korea. However, hemoglobinopathy in children has been reported more frequently than in past with the recent advancement of molecular testing. The purpose of this study was to investigate the clinical and laboratory findings, prevalence and complications of hemoglobinopathy of children.METHODS: Data of pediatric patients diagnosed with hemoglobinopathy from 2002 to February 2014 at Ajou University Hospital were surveyed. We analyzed patients' characteristics from clinical and laboratory findings retrospectively.RESULTS: Among a total of 10 children who were diagnosed with hemoglobinopathy, 9 patients were confirmed hemoglobinopathy by gene analysis. Eight patients had beta thalassemia, 1 hemoglobin D disease, and 1 hemoglobin Koriyama. In most of the children, anemia was found incidentally and most of the children did not have symptoms. In the initial blood test, their mean hemoglobin concentration was 10.0 g/dL (range: 4.7-11.2 g/dL), mean corrected reticulocyte count was 3.9% (range: 0.9%-12.2%), and mean total bilirubin level was 1.0 mg/dL (range: 0.3-5.8 mg/dL).CONCLUSION: The analysis of clinical and laboratory features showed that the characteristics of each type of hemoglobinopathy were similar to that previously reported. We recommend considering hemoglobinopathy if pediatric patient presents with hemolytic anemia. A well organized diagnostic approach including molecular genetic analysis is needed for accurate diagnoses and appropriate management of hemoglobinopathy.

A Clinical Study on Hereditary Hemoglobinopathy: a Single Institute Experience / 임상소아혈액종양

BACKGROUND: Hemoglobinopathy is inherited anemia characterized by abnormal structure of one of the globin chains of the hemoglobin molecule and has been known to be rare in Korea. However, hemoglobinopathy in children has been reported more frequently than in past with the recent advancement of molecular testing. The purpose of this study was to investigate the clinical and laboratory findings, prevalence and complications of hemoglobinopathy of children. METHODS: Data of pediatric patients diagnosed with hemoglobinopathy from 2002 to February 2014 at Ajou University Hospital were surveyed. We analyzed patients' characteristics from clinical and laboratory findings retrospectively. RESULTS: Among a total of 10 children who were diagnosed with hemoglobinopathy, 9 patients were confirmed hemoglobinopathy by gene analysis. Eight patients had beta thalassemia, 1 hemoglobin D disease, and 1 hemoglobin Koriyama. In most of the children, anemia was found incidentally and most of the children did not have symptoms. In the initial blood test, their mean hemoglobin concentration was 10.0 g/dL (range: 4.7-11.2 g/dL), mean corrected reticulocyte count was 3.9% (range: 0.9%-12.2%), and mean total bilirubin level was 1.0 mg/dL (range: 0.3-5.8 mg/dL). CONCLUSION: The analysis of clinical and laboratory features showed that the characteristics of each type of hemoglobinopathy were similar to that previously reported. We recommend considering hemoglobinopathy if pediatric patient presents with hemolytic anemia. A well organized diagnostic approach including molecular genetic analysis is needed for accurate diagnoses and appropriate management of hemoglobinopathy.