• Journal of Genetic Medicine
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• v.17 no.1
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• pp.16-20
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• 2020

Purpose: Duodenal atresia (DA) and atrioventricular septal defect (AVSD) are well known ultrasonographic findings associated with Down syndrome. The risk of Down syndrome in fetuses with these anomalies has been reported as 30% to 40%. However, on the basis of our clinical experience, the risk of Down syndrome of DA may be lower in Korean population. To clarify this issue, we compared the risk of Down syndrome between cases with DA and AVSD. Materials and Methods: The study population consisted of neonates who were confirmed as DA or AVSD by postnatal diagnosis. Postnatal diagnosis was made by surgery, postnatal echocardiography, or autopsy. Medical record was reviewed retrospectively. Results: A total of 213 neonates with DA or AVSD were included: 67 cases with DA and 146 cases with AVSD. The risk of Down syndrome was 4.5% (3/67) in DA vs. 29.5% (43/146) in AVSD. When confining analysis to those whose karyotyping were not performed during antenatal period, the risk of Down syndrome were 7.9% (3/38) in DA and 35.4% (35/99) in AVSD. Conclusion: The risk of Down syndrome in cases with DA was much lower in Korean population than previously reported risk in the literature. The significance of some antenatal sonographic markers for Down syndrome may be different according to ethnicity.

• Journal of Genetic Medicine
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• v.5 no.1
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• pp.7-14
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• 2008

Twenty years have passed since a prenatal screening for Down syndrome and neural tube defect was applied to obstetric field. The Quad test (AFP, hCG, uE3, Inhibin-A) of the second trimester and the combination test (PAPP-A, hCG, NT) of the first trimester became popular now. The recent trend of prenatal screening is to combine these two screening tests together in order to increase a detection rate of Down syndrome. Three types of screening methods are introduced as follows; integrated test, sequential test and contingent test. In addition to combination of each test, an incorporation of characteristic ultrasound findings of Down syndrome is suggested for its risk calculation. The absence of fetal nasal bone would be a very useful marker especially in the first trimester screening test. According to a change of way calculating risk of Down syndrome, obstetrician's role will be more increased not by passive participation, but by active participation using ultrasound in risk calculation.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.549-555
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• 2016

This study was an evaluation of the significance of each parameter through aimed at pregnant women subjected to screening test(integrated test) in predicting risk of Down syndrome. We retrospectively analysed the correlation of risk of Down's syndrome with Nuchal Translucency(NT) images measured by ultrasound, Pregnancy Associated Plasma Protein A(PAPP-A), alpha-fetoprotein(AFP), unconjugated estriol(uE3), human chorionic gonadotrophin(hCG) and Inhibin A by maternal serum. As a result, a significant correlation with NT, uE3, hCG, Inhibin A is revealed with Down's syndrome risk(P<.001). In ROC analysis, AUC of Inhibin A is analysed as the biggest predictor of Down's syndrome(0.859). And the criterion for cut-off was inhibin A 1.4 MoM(sensitivity 81.8%, specificity 75.9%). In conclusion, Inhibin A was the most useful in parameters to predict Down's syndrome in the integrated test. If we make up for the weakness based on the cut-off value of parameters they will be able to be used as an independent indicator in the risk of Down's syndrome screening.

• Korean Journal of Applied Biomechanics
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• v.29 no.3
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• pp.137-143
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• 2019

Objective: Ligament laxity and hypotonia are characteristics of Down syndrome patients. The aim of this study was to compare the landing pattern between Down syndrome patients and typically developing subjects. To compare the landing pattern, variables related to ligament laxity and hypotonia i.e. vertical stiffness and lower extremities kinematics were investigated. Method: Five subjects with Down syndrome (age: $14.6{\pm}1.8years$, mass: $47.6{\pm}6.94kg$, height: $147.9{\pm}6.0cm$) and six able-bodied subjects (age: $13.2{\pm}0.4years$, mass: $54.7{\pm}6.7kg$, height: $160.1{\pm}9.8cm$) participated in this study. Results: The vertical displacement of the center of mass, vertical reaction force, leg stiffness and range of ankle angle range among Down syndrome patients were significantly different than typically developing group. The youth with Down's syndrome appeared to receive greater vertical impact force at landing than normal youth. Conclusion: The differences in the biomechanical characteristics suggest the delay in motor development among Down syndrome patients and an increased risk of injury to the lower extremity during movement execution such as drop landing.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.2
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• pp.201-206
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• 1994

Down syndrome is one of the major chromosomal anomalies in Korea. To decrease incidence of Down syndrome, antenatal diagnosis is essential. At present, antenatal diagnosis of Down syndrome is done by karyotyping from chorionic villus sampling, amniocentesis, and cordocentsis. All these methods have some problems such as a risk of abortion, a long waiting time, difficulties in sampling, and so on. The aim of study was to confirm that PCR(Polymerase Chain Reaction) using D21S11 primer could be a diagnostic tool for Down syndrome. PCR using D21S11 primers with $^{32}P$ labeling at 5' end was done in 21 cases of DNA from 21 Trisomy and 20 cases of DNA from normal karyotype. PCR product was running for 10 hours on the 6% polyacrylamide gel under 1,000 V or for 8 hours under 1,500 V. After X-ray film exposure, it was read by densitometry. Normal group showed 1: 1 band or single band. 21 Trisomy group showed 1.3-2: 1 band or 2.3 times of density compared to normal single band or 3 bands. This method gave the result within 24 hours. It can be an useful diagnostic tool to detect 21 Trisomy antenatally, especially in late pregnancy, and in preimplantation diagnosis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.314-320
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• 2021

With the increasing age of motherhood in recent years, attributed to late marriages due to social or environmental factors, the Down's syndrome screening test using biochemical markers has become essential for pregnant women. The process of diagnosing Down's syndrome pregnancy in the high-risk group subjects involves chromosomal analysis, which is performed on samples obtained through invasive procedures such as chorionic biopsy or amniotic fluid. Thus, to reduce unnecessary invasive tests and lower the risk to mother and fetus, it is important to identify a screening test with low risk and high Down's syndrome detection rate. Recently, as the average age of mothers has increased, numerous inspection agencies have classified high-risk mothers as women over the age of 35 years. This study evaluated a total of 36,436 pregnant women aged between 17 to 46 years, and who requested prenatal screening at an inspection agency in Yongin in 2018. Test (13,690 people) Four tests were conducted by applying the time-resolved fluoroimmunoassay method using the direct sandwich and indirect sandwich technology, and the immunoassay method using the sandwich method. We aimed to confirm the difference in positivity rate with increasing age of the subjects. We believe that in future, data obtained from this study will be very useful for the prevention and treatment of Down's syndrome risk at varied inspection institutions, and for prospective mothers.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.1
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• pp.56-60
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• 2005

Human chorionic gonadotrophin (hCG) and unconjugated estriol (uE3) were added to AFP to make what is commonly known as the Triple test. The Triple test combines results from these three tests and has been a standard screening procedure for several years. Recent studies have demonstrated the usefulness of adding inhibin-A to Down's syndrome risk assessment. The Quad test adds dimeric Inhibin-A (DIA) to the three other markers and uses the same computer program to calculate risk factors. Testing was performed between 14 and 21 weeks of gestation. Sample size were 648 samples and period of study was from 1, July, 2004 to 30, September, 2004. Used analytical methods for AFP, hCG and uE3 were radioimmunoassay (RIA) and dimeric inhibin A was enzyme-linked immunosorbent assay (ELISA). Adding dimeric inhibin-A as a fourth marker to the standard triple test increases the detection rate from 62 % to 75 % with a false-positive rate of 5%. The DIA based Quad test has been shown to be the most effective second trimester screening test for Down's syndrome suitable for routine use. Increased DIA values are observed during normal pregnancy where a bimodal pattern response is seen. Values increase during the first trimester, decline after 14 weeks, and re-ascend between 17-25 weeks. Values for DIA may be additionally elevated during a Down's syndrome pregnancy. Dimeric inhibin A is a glycoprotein hormone made by the ovary and placenta. DIA levels are twice as high in Down's syndrome pregnancies. AFP, hCG, and uE3 levels vary with gestational age, and incorrect gestational dating will influence results. DIA levels do not vary substantially with gestational age, resulting in greater screening accuracy. Although the Quad test is an improvement over the Triple test, it is important to underscore the fact that a positive test on both should be done. Most women who initially screen positive will be found to be carrying normal babies when amniocentesis and definitive diagnostic chromosome analysis are done.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.225-231
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• 2018

Down syndrome patients generally have poor oral hygiene due to lack of awareness and ability to perform oral care, and there is a high risk of tooth loss. Also, they are characterized by small and irregular teeth and oligodontia, which makes it difficult to do prosthetic treatment. This article reports a case of implant hybrid prosthesis treatment of maxillary edentulous area in Down syndrome patient. The external shape of the final prosthesis was determined by using the mandibular artificial teeth to reflect the oligodontia of the mandible and the pontic areas were adjusted to facilitate oral hygiene care. As a result, aesthetically and functionally satisfactory results were obtained.

• Journal of Yeungnam Medical Science
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• v.40 no.2
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• pp.187-192
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• 2023

Background: This study aimed to present the short- and midterm outcomes after complete atrioventricular canal defect (CAVC) repair using a single-patch technique. Methods: This study included 30 children who underwent surgical correction of the CAVC using a single-patch technique. Results: The median age of the patients was 5.7 months (interquartile range [IQR], 5.0-7.5 months), and 23 patients (76.7%) had type A CAVC. Fourteen patients (46.7%) were female and 17 (56.7%) had been diagnosed with Down syndrome. The in-hospital mortality rate was 0%. No deaths were observed during a median follow-up of 4 years (IQR, 3.5-5.0 years). Patients without Down syndrome were associated with late moderate mitral regurgitation (MR) (p=0.02). Late MR less than moderate degree was observed in 96.6%, 78.5%, and 50% of patients after 2, 4, and 5 years of follow-up, respectively, while late tricuspid valve regurgitation less than moderate degree was observed in 96.7%, 85.9%, and 59.0% of patients after 2, 4, and 6 years of follow-up, respectively. After a median follow-up of 4 years, only one patient had required surgical repair of a left ventricular outflow tract obstruction, which occurred 26 months after the first operation. Multivariable logistic regression analysis adjusted for the type of CAVC, sex, Down syndrome, age, and weight revealed that the absence of Down syndrome was a risk factor for late moderate MR (MR-2) (odds ratio, 0.05; 95% confidence interval, 0.006-0.50; p=0.01). Conclusion: A single-patch technique for CAVC surgical repair is a safe method with acceptable short- and midterm results.

• Environmental Analysis Health and Toxicology
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• v.31
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• pp.1.1-1.13
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• 2016

Objectives To investigate the accuracy and scientific validity of the current very low risk factor for hereditary diseases in humans following exposures to ionizing radiation adopted by the United Nations Scientific Committee on the Effects of Atomic Radiation and the International Commission on Radiological Protection. The value is based on experiments on mice due to reportedly absent effects in the Japanese atomic bomb (A-bomb) survivors. Methods To review the published evidence for heritable effects after ionising radiation exposures particularly, but not restricted to, populations exposed to contamination from the Chernobyl accident and from atmospheric nuclear test fallout. To make a compilation of findings about early deaths, congenital malformations, Down's syndrome, cancer and other genetic effects observed in humans after the exposure of the parents. To also examine more closely the evidence from the Japanese A-bomb epidemiology and discuss its scientific validity. Results Nearly all types of hereditary defects were found at doses as low as one to 10 mSv. We discuss the clash between the current risk model and these observations on the basis of biological mechanism and assumptions about linear relationships between dose and effect in neonatal and foetal epidemiology. The evidence supports a dose response relationship which is non-linear and is either biphasic or supralinear (hogs-back) and largely either saturates or falls above 10 mSv. Conclusions We conclude that the current risk model for heritable effects of radiation is unsafe. The dose response relationship is non-linear with the greatest effects at the lowest doses. Using Chernobyl data we derive an excess relative risk for all malformations of 1.0 per 10 mSv cumulative dose. The safety of the Japanese A-bomb epidemiology is argued to be both scientifically and philosophically questionable owing to errors in the choice of control groups, omission of internal exposure effects and assumptions about linear dose response.