Kyu Hyung Lee

Testicular hypoplasia in monochorionic dizygous twin with confined blood chimerism

Monochorionic diamniotic (MCDA) twins identified by ultrasound in early pregnancy are rarely dizygotic. Since Shouter et al. first reported that MCDA twin pregnancies can occur in dizygous (DZ) twin pregnancies, there have been about ten reports of such cases [1]. MCDZ twins can be easily overlooked except in cases of discordant sex discovered during prenatal care or delivery of MCDA twins. In our case, chimerism of a set of MCDZ twins was confirmed by STR analysis for both parents and the live male twin after the discovery of discordant sex in a pair of MCDA twins at delivery. Testicular atrophy was suspected in a follow-up sonogram of the testes of the live male twin; Testicular hypoplasia was revealed by a subsequent testicular biopsy. We report herein a rare case of testicular hypoplasia in a male infant with chimerism that was observed on follow-up examination after birth.

22q11.2 Microduplication with thyroid hemiagenesis.

Background: Chromosome 22q11.2 microduplications are extremely rarely detected; in comparison, the deletion of same region, known as the DiGeorge/velocardiofacial syndrome, occurs more frequently. Thyroid anomalies commonly occur in patients with 22q11.2 deletion syndrome, however few reports of thyroid anomalies associated with 22q11.2 microduplication have been published thus far. Case Report: We present a case of a male infant who was prenatally diagnosed with 22q11.2 microduplication and was found to have congenital hypothyroidism due to thyroid hemiagenesis after birth. Moreover, the baby had bilateral hearing impairment, bilateral cryptorchidism, and a rotated penis. At the age of 2 years, the infant was euthyroid with levothyroxine replacement, but he showed significant developmental delay. Conclusions: To our knowledge, this is the first case of congenital hypothyroidism with thyroid hemiagenesis in a patient showing 22q11.2 microduplication. Thyroid dysgenesis could be an additional clinical feature shared by the 22q11.2 microduplication and deletion syndrome, suggesting that the duplication and deletion of a gene may result in a common phenotype. Thyroid dysgenesis should be considered in the evaluation and management of patients with this genomic disorder.

Low levels of tissue inhibitor of metalloproteinase-2 at birth may be associated with subsequent development of bronchopulmonary dysplasia in preterm infants.

Purpose Bronchopulmonary dysplasia (BPD) is characterized by inflammation with proteolytic damage to the lung extracellular matrix. The results from previous studies are inconsistent regarding the role of proteinases and antiproteinases in the development of BPD. The aim of the present study was to investigate whether matrix metalloproteinase (MMP)-8, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-2, and TIMP-1 levels in the serum of preterm infants at birth are related to the development of BPD. Methods Serum was collected from 62 preterm infants at birth and analyzed for MMP-8, MMP-9, TIMP-2, and TIMP-1 by using enzyme-linked immunosorbent assay. MMPs and TIMPs were compared in BPD (n=24) and no BPD groups (n=38). Clinical predictors of BPD (sex, birth weight, gestational age, etc.) were assessed for both groups. The association between predictors and outcome, BPD, was assessed by using multivariate logistic regression. Results Sex, birth weight, and mean gestational age were similar between the groups. BPD preterm infants had significantly lower TIMP-2 levels at birth compared with no BPD preterm infants (138.1±23.0 ng/mL vs. 171.8±44.1 ng/mL, P=0.027). No significant difference was observed in MMP-8, MMP-9, and TIMP-1 levels between the two groups. Multivariate logistic regression analysis indicated that the TIMP-2 levels were predictive of BPD after adjusting for sex, birth weight, gestational age, proteinuric preeclampsia, and intraventricular hemorrhage (β=-0.063, P=0.041). Conclusion Low TIMP-2 serum levels at birth may be associated with the subsequent development of BPD in preterm infants.

Insulin pump therapy in transient neonatal diabetes mellitus

Neonatal diabetes mellitus (NDM) is a rare disease requiring insulin treatment. Its treatment is primarily focused on maintaining adequate glycemic control and avoiding hypoglycemia. Although insulin pump therapy is frequently administered to adults and children, there is no consensus on the use of insulin pumps in NDM. A 10 day-old female infant was referred to us with intrauterine growth retardation and poor weight gain. Hyperglycemia was noted, and continuous intravenous insulin infusion was initiated. However, the patients serum glucose levels fluctuated widely, and maintaining the intravenous route became difficult within the following weeks. Continuous subcutaneous insulin infusion with an insulin pump was introduced on the twenty-fifth day of life, and good glycemic control was achieved without any notable adverse effects including hypoglycemia. We suggest that the insulin pump is a safe and effective mode for treating NDM and its early adoption may shorten the length of hospital stays in patients with NDM.