The Korean collaborative study on 11,000 prenatal genetic amniocentesis

Population Prevalence, Cancer Risk, and Mortality Risk of Turner Syndrome in South Korean Women Based on National Health Insurance Service Data

PURPOSE

In South Korea, investigations into Turner syndrome (TS) prevalence and TS-associated cancer and mortality are lacking. Accurate data were estimated from the National Health Insurance Service (NHIS) and the Rare Diseases Registry (RDR) records.

MATERIALS AND METHODS

Data on patients with TS who were registered in the RDR between 2007 and 2017 were collected. To estimate TS-associated cancer and mortality risk, the data were compared with data of 1:3 age-matched controls.

RESULTS

In 2017, 2054 patients with TS were identified from a total population of 26186952 South Korean women; therefore, the prevalence was 7.84 per 100000 persons. TS prevalence across 10-year interval age groups were 11.82, 23.17, 18.37, 10.49, 4.09, and 0.38 for age under 10 years, teenagers, 20s, 30s, 40s, and older than 50, respectively (per 100000 persons). The cancer risk in patients with TS was higher than that of age-matched controls over 5.3 person-years [hazard ratio (HR)=1.82, 95% confidence interval (CI) 1.01-3.27, p=0.045]. Among different types of cancer, thyroid cancer risk in patients with TS was significantly higher than that of age-matched controls (HR=2.78, 95% CI 1.06-7.26, p=0.037). We also observed that TS-associated all-cause mortality risk was higher than that of age-matched controls (HR=3.36, 95% CI 1.59-7.10, p=0.002).

CONCLUSION

National prevalence of TS was suggested, and an increased risk of TS-associated thyroid cancer and mortality were observed in this study.

Prenatal Diagnosis Nomograms: A Novel Tool to Predict Fetal Chromosomal Abnormalities in High-Risk Patients

Background

Amniocentesis is an invasive prenatal diagnostic technique that can provide genetic information of fetus for pregnant women and give them a choice. A straightforward predictive tool can show pregnant women the need for amniocentesis prior to the procedure.

Methods

The information of patients who underwent amniocentesis from 2014 to 2019 at the Obstetrics Clinic, Shengjing Hospital of China Medical University was extracted, and important independent prognostic factors were determined by univariate and multivariate logistic regression analysis to construct nomograms with total abnormalities (TA) and chromosome number abnormalities (CNA).

Results

A total of 19,683 patients undergoing amniocentesis were included in this study. Among 1761 patients with abnormal results, 917 had abnormal chromosome numbers, 439 had abnormal chromosome structures, and 405 had polymorphic results. Nomograms of TA and CNA were created using data such as age, nuchal translucency value, ultrasound results, Oscar’s testing and/or non-invasive prenatal testing abnormalities, parental chromosomes, and information whether they were twins. The nomogram has good predictive power and clinical practicality through the analysis of area under curve and decision curve analysis. Internal verification was performed for nomograms of TA and CNA, suggesting that the nomogram’s predicted probability and actual probability of the two are consistent.

Conclusion

The nomogram constructed is a good predictor of TA and CNA, which can be used in clinical practice to screen high-risk patients of chromosomal abnormalities.

Relation Between Increased Fetal Nuchal Translucency Thickness and Chromosomal Defects in Northern Vietnam

Objective To examine the prevalence of all chromosomal defects amongst fetuses with increased nuchal translucency thickness (NT). Methods This is a retrospective study amongst pregnant women indicated for amniocentesis by nuchal translucency above 3.0 mm and consent to the study. A total of 2,720 cases were recruited during the six-year period from 2015 to 2020. All singleton pregnancies were offered fetal karyotype when the fetal nuchal translucency was ≥2.5 mm. The prevalence of chromosomal defects was divided into five NT categories: 2.5-3.4 mm, 3.5-4.4 mm, 4.5-5.4 mm, 5.5-6.4 mm, ≥6.5 mm. Results The study identified 2,720 amniocentesis for increased NT. The mean maternal age was 29.19 (range 17-46) years, and the mean fetal crown-rump length was 66.9 (range 45-84) mm. The fetal karyotype was abnormal in 560 (20.6%) participants. The most frequent chromosomal disorders were trisomy 21 (55%), trisomy 18 (11.2%), trisomy 13 (3.9%), 45,XO (2.7%). The prevalence of chromosomal aberrations was ranged from 17.9% (NT between 2.5-3.4 mm) to 29.7% (NT≥6.5 mm). A majority of fetuses with trisomy 13, 18, or 21 has NT measurement lower than 5.5 mm. In those with Turner syndrome, there was no difference between the group with NT <5.5 mm and the group with NT ≥5.5 mm. Increased maternal age is a risk factor for chromosomal aberrations with the rate increased from 17.6% at the youngest maternal age of 30-34 to 34% at maternal age of 35-39 and to 50% at maternal age of ≥40. Conclusion In fetuses with increased NT, more than a half of the chromosomal abnormalities were affected by defects other than trisomy 21. The distribution of NT was different between Turner syndrome and trisomy 13, 18, 21 syndromes. Women aged 35 years or older had a higher risk of chromosomal aberrations.

Prenatal cytogenetic diagnosis in Taiwan: a nationwide population-based study

PURPOSE

The goal of this study was to gain a better understanding of the status of advanced maternal age among criteria for provision of amniocentesis in pregnant women in Taiwan.

MATERIALS AND METHOD

Data of 315 670 second-trimester amniocenteses from 28 national certified cytogenetics laboratories were retrospectively analyzed from the Prenatal Genetic Diagnosis Declaring and Database System of the Health Promotion Administration, Ministry of Health and Welfare in Taiwan between 2006 and 2013.

RESULTS

The number of pregnant women undergoing amniocentesis in Taiwan between 2006 and 2013 increased, and the most common three indications for amniocentesis were advance maternal age (75.11%), abnormal second trimester maternal serum screening (13.22%) and abnormal sonographic finding (8.00%). Down syndrome was the most common autosomal abnormality identified (25.74%); Turner syndrome was the most common sex chromosome abnormality (7.04%). Of structural rearrangements, 26.93% were balanced translocations and 17.10% were unbalanced translocations. The greatest proportion of fetal chromosomal abnormalities was found in cases where parents were also affected (38.02%).

CONCLUSIONS

Clinical workers should provide detailed genetic diagnostic information to pregnant women, especially those with the common amniocentesis indications, which will enable them to determine a birth plan.

The importance of rapid aneuploidy screening and prenatal diagnosis in the detection of numerical chromosomal abnormalities

Objectives

Evaluation of Fluorescent in situ hybridization (FISH) as a tool for rapid aneuploidy screening (RAS) of high risk pregnancies, before its approval in the national antenatal screening and genetic diagnosis program in Egypt.

Methods

The cytogenetic data of prenatal specimens, and results of FISH of 100 patients performed between, January 2009 and December 2009, at the Medical Genetics Center (MGC) laboratory were retrieved and reviewed. AneuVysion Assay kit was used for detection of 13, 21, X, Y, 18 aneuploidies.

Results

Maternal age varied from 21 to 44 years (mean was 35.6 year). Ninety percent of pregnancies had normal chromosomes and 10% of the cases had numerical chromosomal abnormalities. Trisomy 21 was the most frequent chromosomal disorder across all indications (5%), followed by Turner syndrome (2%), trisomy 18 (2%), and trisomy 13 (1%). When comparing the FISH data with karyotype results for chromosomes 13, 18, 21, X, and Y in the 83 individual tested, no false positive or negative results were detected by the FISH assay. The result obtained by FISH and the banding cytogenetic were in complete accordance.

Conclusion

This study supports the integration of amniotic fluid (AF) FISH as a RAS test, in to routine antenatal practice for identification of chromosome aneuploidies. There are trends towards delayed childbearing and most cases of Down Syndrome (DS) are currently detected post-nataly in the Egyptian population. Consequently, the live birth prevalence of DS has increased, which might lead to a serious negative public health effects.

Extra G-positive band at chromosome 9q13 as a recurrent heteromorphism in a Korean population

The extra G-positive, C-negative band within 9q13 has been repeatedly found during chromosomal analyses of amniocenteses with a frequency of 2.4 in 1000 (28 cases in 11,890 chromosomal analyses) in the Korean population. All of the carrier parents with this variant did not have any phenotypic abnormalities and 10 cases that were followed after birth showed that all, except 1 patient with duodenal atresia, had no apparent phenotypic abnormalities. The results of Agilent 244 K oligonucleotide array CGH showed no changes of genomic dosages. We can be sure that the extra bands present are heterochromatic materials of no clinical significance.