We aimed to investigate the changes in vitamin D levels and factors associated with vitamin D deficiency (VDD) during the first year of life in Korean preterm infants. We enrolled 333 preterm infants who were born at Kyungpook National University Children’s Hospital between March 2013 and December 2019. 25-hydroxyvitamin D (25-OHD) levels and medical records were collected at birth, 6 months, and 12 months of age. The mean gestational age was 33.4 ± 2.3 weeks and mean 25-OHD levels at birth were 18.2 ± 13.5 ng/mL. The incidence of VDD was 82.8%, 30.6%, and 27.0% at birth, 6 months, and 12 months, respectively. The incidence of severe VDD (25-OHD < 10 ng/mL) was 31.5%, 1.5%, and 0%, at birth, 6 months, and 12 months, respectively. Among infants with severe VDD, the deficiency persisted in 49.6% at 6 months, and 35.3% at 12 months. The strongest predictor of VDD during follow-up was 25-OHD concentration at birth. Vitamin D supplementation at 400 IU/day did not affect vitamin D levels during the first year of life. Therefore, it is important to prevent neonatal VDD through maternal vitamin D supplementation during pregnancy. Further research is needed to determine the optimal vitamin D supplementation dose for Korean preterm infants.

Purpose: To evaluate the incidence rate, clinical characteristics, and perinatal outcomes of pneumothorax in late preterm and full-term newborns with respiratory distress and analyze the risk factors associated with pneumothorax.Methods: Infants born at ≥34 weeks’ gestation with respiratory distress and pneumothorax admitted between February 2014 and December 2020 were enrolled in this study. The pneumothorax group (n=36) was matched to the control group (n=144) in a 1:4 ratio, based on gestational age and birth weight. Risk factors were identified using logistic regression analysis with backward stepwise selection.Results: The incidence of pneumothorax during the study period was 1.36% (38/2,788). All patients were diagnosed with pneumothorax within 48 hours after birth, and increased oxygen demand was the most common symptom. The proportion of mortality and perinatal morbidity, such as intraventricular hemorrhage ≥grade 3, was significantly higher in the pneumothorax group than in the control group. The risk factors associated with pneumothorax were the need for positive pressure ventilation in the delivery room (odds ratio [OR], 3.40; 95% confidence interval [CI], 1.26 to 9.12; P=0.015) and a higher fraction of inspired oxygen to achieve an oxygen saturation of ≥90% on admission (OR, 1.06; 95% CI, 1.03 to 1.09; P<0.001).Conclusion: Pneumothorax should be suspected in late preterm and full-term newborns with respiratory distress within the first 3 days of life. Based on these risk factors, early diagnosis can reduce perinatal mortality and morbidity.

Oculocutaneous albinism (OCA) is a group of rare genetically heterogeneous disorders, characterized by hypopigmentation of the eyes, skin, and hair, which result in ocular abnormalities and a risk of developing skin cancer. Currently, there is no ophthalmologic procedure or drug that prevents the clinical features of OCA. Here, we report a new type of OCA in two, unrelated Korean families with the same OCA2 mutation. Affected individuals in this study are different from those of previous reports in two aspects: an inheritance pattern and clinical presentation. All reported patients with OCA have shown an autosomal recessive inheritance pattern, while our patients showed an autosomal dominant inheritance pattern. Small amounts of pigment can be acquired with age in OCA, but there is no substantial variation from adolescence to adulthood in this regard. A case where the patient attained normal pigmentation levels has never been reported. However, our patients displayed completely normal pigmentation in their late twenties. Whole exome sequencing and in-silico analysis revealed a novel mutation, OCA2 c.2338G>A p.(G780S) (NM_000275) with a high likelihood of pathogenicity. Sanger sequencing of p.G780S identified the same mutation in the affected individuals, which was not found in the family members with normal phenotype. We hypothesize that OCA2 G780S not only acts as a pathogenic variant of OCA but also induces pigmentation by enhancing the melanogenesis gene expression of other modifier genes, such as SLC45A2 and TPC2. These findings may provide further understanding of melanin biosynthesis and new treatment methods for OCA.

We aimed to determine the incidence of acute kidney injury (AKI) and longitudinal changes in SCr levels and urinary biomarkers associated with AKI and aminoglycoside (AG) medication during the first week of life of late preterm infants. Urine biomarkers and SCr were measured in thirty late preterm infants on days one, two, five, and seven postnatal. Urine biomarkers included neutrophil gelatinase-associated lipocalin (NGAL), monocyte chemotactic protein-1 (MCP-1), epidermal growth factor (EGF), Tamm–Horsfall glycoprotein (THP), and liver fatty-acid-binding protein (L-FABP). Gestational age was positively correlated with SCr levels at birth, but inversely correlated with SCr levels at day five and day seven. Eighteen (60%) infants had stage 1 AKI, and twenty (67%) infants were treated with AGs. Infants with AKI had lower gestational age and lower birth weight than those without AKI. Urinary biomarkers adjusted according to uCr levels in infants with AKI were not statistically different from those in infants without AKI. There were no significant differences in incidence of AKI, and SCr levels during and after cessation of AG treatment. The uMCP-1/Cr ratio at days five and seven was higher in infants treated with AG than in non-treated infants.

Kleefstra syndrome is a rare genetic disease characterized by mental retardation, hypotonia, and a characteristic facial appearance. Furthermore, in some cases, Kleefstra syndrome is associated with various anorectal and genitourinary complications, including imperforated anus, vesicoureteral reflux, hydronephrosis, and chronic kidney disease. Herein, we present a case of Kleefstra syndrome with recurrent urinary tract infections associated with vesicoureteral reflux and rectourethral fistula, which was treated by a multidisciplinary approach.

Fetal ventriculomegaly (VM) is a relatively common finding during prenatal examinations and occurs in approximately 0.2% of live births. Although there are various causes, obstructive VM due to cerebellar hemorrhage is exceedingly rare. A 33-year-old primigravida presented at 32 weeks of gestation with VM. At 36 weeks of age, a male infant was delivered via cesarean section. Postnatal imaging revealed severe bilateral hydrocephalus and space-occupying lesions in the cerebellum. Initial concerns about a potential germ cell tumor were raised due to elevated alpha-fetoprotein levels in both serum and cerebrospinal fluid. An external ventricular drain was placed to manage obstructive hydrocephalus. When the baby was 1 month old, surgical exploration revealed an old blood clot without any evidence of a tumor. Histopathological examination confirmed an old hemorrhage with no malignant cells. This case underscores the diagnostic challenges in distinguishing between hemorrhages and tumors in the context of fetal VM. Despite elevated alpha-fetoprotein levels, no tumors were identified. The underlying cause of cerebellar hemorrhage remains unclear despite extensive workups. Nevertheless, this case report details multifaceted diagnostic efforts to address the rare occurrence of cerebellar hemorrhage related to fetal VM, leading to a comprehensive case presentation.