Complete or partial triplication of human chromosome 21 results in Down syndrome (DS). To analyze differential gene expressions in amniotic fluid (AF) cells of DS, we used a DNA microarray system to analyze 102 genes, which included 24 genes on chromosome 21, 28 genes related to the function of brain and muscle, 36 genes related to apoptosis, 4 genes related to extracellular matrix, 8 genes related to other molecular function and 2 house-keeping genes. AF cells were collected from 12 pregnancies at 16-18 weeks of gestation in DS (n=6) and normal (n=6) subjects. Our DNA microarray experiments showed that the expressions of 11 genes were altered by at least 2-folds in DS, as follows. Ten genes, COL6A1, CASP5, AKT2, JUN, PYGM, BNIP1, OSF-2, PRSS7, COL3A1, and MBLL were down-regulated and GSTT1 was only up-regulated. The differential expressions of GSTT1 and COL3A1 were further confirmed by semi-quantitative RT-PCR for each sample. The gene dosage hypothesis on chromosome 21 may explain the neurological and other symptoms of DS. However, our results showed that only two genes (COL6A1 and PRSS7), among 24 genes on chromosome 21, were down-regulated in the AF cells of DS. Our data may provide the basis for a more systematic identification of biological markers of fetal DS, thus leading to an improved understanding of pathogenesis for fetal DS.

Although many molecular detection methods have been employed to monitor insecticide resistance, the present microarray provides rapid and accurate identification of target mutations in B. tabaci for resistance management.

Background: Despite the importance of and social concern regarding prevention of diabetes at younger ages, limited data are available. This study sought to analyze changes in the prevalence of type 2 diabetes mellitus (T2DM) in Koreans younger than 30 years according to sex, age, and level of income. Methods: The dataset analyzed in this study was derived from health insurance claims recorded in the National Health Insurance Service (NHIS) database. Participants' level of income was categorized as low (quintile 1, <20% of insurance premium) or others (quintile 2-5). Results: In males and females, the prevalence of T2DM per 10,000 people steadily increased from 2.57 in 2002 to 11.41 in 2016, and from 1.96 in 2002 to 8.63 in 2016. The prevalence of T2DM in girls was higher in the age group of 5 to 14 years. Even though the prevalence was higher among those older than 20 years, the increase had started earlier, in the early 2000s, in younger age group. Adolescents aged 10 to 19 years in low-income families showed a remarkable increase in prevalence of T2DM, especially in boys. Conclusion:The prevalence of T2DM in young Koreans increased more than 4.4-fold from 2002 to 2016, and the increase started in the early 2000s in younger age groups and in low-income families. This is the first study to examine the trend in prevalence of T2DM in children, adolescents, and young adults in Korea. Future studies and collaborations with social support systems to prevent T2DM at an early age group should be performed.

Background: Children experience seasonal variations in growth whereby height increases most in spring and least in autumn, and weight increases least in spring and most in autumn. We hypothesized that activity restriction caused by efforts to contain the spread of coronavirus disease 2019 (COVID-19) would result in increased body mass index (BMI) in children, differing from conventional seasonal growth variations. Methods: We included 169 children who visited endocrine clinics of three hospitals in Korea at regular intervals under the same conditions for two years. Visit dates were D1 (January, 2019), D2 (July, 2019), D3 (January, 2020) before the COVID-19 outbreak, and D4 (July, 2020) during the pandemic. Differences in the z-score for height (HT), weight (WT), and BMI among time points and between spring seasons (i.e., S1–S3) were compared. Results: There were significant differences in BMIz among time points, which decreased from D1–D2 and increased from D2–D3 and D3–D4. WTz significantly increased from D2–D3 and D3–D4. BMIz values of S1 (spring 2019) and S3 (spring 2020) were −0.05 and 0.16, respectively, showing significant differences. WTz values between S1 and S3 were significantly different (−0.02 vs. 0.13). Conclusions: In 2019, there were conventional seasonal variations in BMIz, which declined in spring and increased in autumn, while in 2020, BMIz increased even in spring. The COVID-19 pandemic may have affected seasonal variations in the growth of children attending endocrine clinics.