Fluorescence in Situ Hybridization (FISH) is cytogenetics - molecular technique. FISH is the rapid detection technique of chromosomal aberration by chromosome specific probes applied to interphase cells. In this study, the authors used Kit duple DNA probe for chromosome 13, 21, X, Y to prenatal diagnosis of Down’s syndrome. With 6 amniotic fluid samples, the authors obtained the results as follows: 2 samples were Down’s syndrome trisomy; 1 sample was Patau syndrome trisomy; 3 samples were normal; 1 sample male foetus died without clear causes. Cytogenetic result: 46, XX but FISH result: 46, XY; PCR (Polymerase Chain Reaction) result: TDF (Testis Determining Factor): (+). These results were confirmed by chrosome analysis.
Down Syndrome ; Prenatal Diagnosis

The total 76 children from one month of age to fourteen years of age have been determined as phenotypic features and karyotypes of Down's syndrome. The distribution is as follow: typical trisomy is 69 cases (90%), translocation is 4 cases (5.26%), mosaism is 3 cases (3.95%). The mean maternal age at the birth of Down's patients was 30.8±2.2. The mean paternal age at the birth of Down's patients was 33.9±1.7. Maternal age distribution at the birth of Down's patients: The frequency was lowest in the mothers under 20 years old. It increases at age 25-29, then it decreased and increased again after the age 35-39. Chromosome studies have been made also on the patients, whose karyotypes are all normal (46,XX or 46,XY). The pedigrees of all patients were made. It has no one who has two patients in the same family
Down Syndrome ; diagnosis

No abstract available.
Down Syndrome* ; Prenatal Diagnosis* ; Ultrasonography*

Background: The fetus having risk for Down sydrome (DS) can be detected early by AFP, \u03b2hCG in maternal serum to detect the fetus having risk of Down sydrome. Objectives: Determining values of AFP, \u03b2hCG in maternal serum to detect the fetus having risk of DS. Subjects and method: Determining the concentration of AFP, \u03b2hCG in maternal serum of 591 pregnant with fetus \ufffd?12 weeks to detect the fetus having DS screening risk. The fetus are diagnosed DS by analysing chromosome from amniocyte and monitor up to the neonate. Then, finding out association between DS fetus and AFP, \u03b2hCG in maternal serum. Results: 75/591 of subjects screened were screen positive, 6/7 DS fetus associated withscreen positive, (cut off AFP \ufffd?0,75 MoM, \u03b2hCG \ufffd?2,2 MoM). Detection rate (DR) was 85,71%; false positive rate (FDR): 11,81%. Only base on AFP: DR was 71,43%; FDR: 11,81%. Only base on \u03b2hCG DR was 28,57%; FDR: 0,51%. Conclusion: DR base on AFP is higher than base on \u03b2hCG. If combining AFP and \u03b2hCG, DR is the highest. AFP is important role in screening DS fetus.
Down Syndrome/ diagnosis ; Predictive Value of Tests ; Prenatal Diagnosis ; Pregnancy ;

The purpose of this study was to evaluate the bone age and hand anomaly in Down syndrome patients. We reviewed radiographs in 52 children and youths with Down syndrome, aged from 2 to 23 years. The characteristic findings of hand anomaly were observed in the middle phalanx of the fifth finger, with the following incidence; brachymesophalangia (44%), clinodactyly (48%), and dysmesophalangia (15%). Pseudoepiphysis (21%) was found typically at the distal end of the first metacarpal bone and proximal end of the second metacarpal bone. Up to 8.5 years of age, bone maturation was retarded and thereafter bone age accelarated in advance of chronologic age. These findings may provide valuable information relative to the diagnosis and treatment of hand anomaly in Down syndrome.
Adolescent ; Child ; Diagnosis ; Down Syndrome* ; Fingers ; Hand* ; Humans ; Incidence

Serological prenatal screening tests are widely used to detect fetal chromosomal abnormalities such as Down and Edward syndromes. Amniocentesis is conducted as a confirmatory test in the screening-positive case. After discovering of presence of fetal cell-free DNA in maternal blood, non-invasive prenatal test (NIPT) coupled with next generation sequencing are performed in abroad. Results of genomics-based NIPT results supplied to Labgenomics laborotory from June, 2013 to August, 2014 were analyzed. Maternal blood samples were collected into specific Cell-Free DNA BCT tube and were transported. The samples were then delivered to Ariosa Diagnostics by FEDEX. Fetal cell-free DNA samples were analyzed using the Harmony test with sequencing of relevant chromosomes and by using the FORTE (fetal-fraction optimized risk of trisomy evaluation) algorism at Ariosa Diagnostics. In all, 149 cases from 28 medical clinics were analyzed. Six subjects were required recollection of samples because of a low fetal DNA fraction in the initially obtained samples. Of these 6 subjects, no sample could be collected from one. Of the remaining 148 cases, 144 had a low risk of trisomy, and 4 had a high risk for Down syndrome, thus providing a positivity percentage of 2.7%. Fetal DNA fraction in the maternal blood samples ranged from 4.2% to 23.7% with a mean value of 12.0%. We have experienced cases with a high risk for Down syndrome with genomics-based NIPT referred to abroad.
Amniocentesis ; Chromosome Aberrations ; DNA ; Down Syndrome ; Prenatal Diagnosis ; Trisomy

Background: FISH can detect number and structural chromosome aberrations in DNA. FISH is new technique in Vietnam, we combine FISH with chromosome analysis to prenatal diagnosis Down syndrome and turner syndrome that are high rate in birth defect.Objectives: To detect Down syndrome and turner syndrome by using FISH technique with chromosome analysis from amniotic cell.Subjects and method: 14amniotic cells samples 15th - 20th week with high risk of birth defects. Advance using FISH and chromosome analysis from amniotic cell. Results: We obtained results as follow: - 14/14 samples: correspondence between FISH and chromosome analysis. \ufffd?Detected 2 Down syndrome (female. Trisomi 21) and 4 Turner syndrome (45, X). Conclusion: Detected Down syndrome and Turner syndrome by using FISH technique with chromosome analysis from amniotic cell.
Down Syndrome/ diagnosis ; Turner Syndrome/ diagnosis ; Predictive Value of Tests ; Prenatal Diagnosis ; In Situ Hybridization ; Fluorescence ;

OBJECTIVE: To evaluate the efficacy of non-invasive prenatal testing (NIPT) in the prenatal screening and its role in the system of prenatal diagnosis. METHODS: A total of 22 649 singleton pregnant women who were registered and finally delivered or had induced labor at Beijing Obstetrics and Gynecology Hospital of Capital Medical University were enrolled. The routes of prenatal screening were analyzed to evaluate the efficacy of prenatal screening. Meanwhile, 9268 pregnant women who underwent invasive prenatal diagnosis procedure were enrolled. The indications and results of prenatal diagnosis were analyzed to evaluate the effectiveness of prenatal screening. RESULTS: 60.24% of singleton pregnant women have opted for Down syndrome screening, and their age was mainly under 35. The proportion of women opted for NIPT was 34.74%, and were mainly between 35 and 39. The overall diagnostic rate of trisomy 21, 18 and 13 trisomy for those with high risk by NIPT was 0.89%, which yielded a positive predictive value of 75.71%. For those with moderate risk by serum screening, 0.30% was predicted with a high risk by NIPT. Among women undergoing prenatal diagnosis, 63.04% and 21.22% had the indication of advanced age or high risk by serum screening, and the positive predictive values were 5.1% and 5.13%, respectively. By contrast, 2.30% of women undergoing prenatal diagnosis had a high risk by NIPT, which yielded a positive predictive value of 54.46%. CONCLUSION With the change of the age composition of pregnant women and increase in the complexity of pregnancy in China, to build a prenatal screening system based on NIPT will be helpful to improve the efficiency of the current system of prenatal screening and diagnosis.
China ; Down Syndrome/genetics* ; Female ; Humans ; Pregnancy ; Prenatal Diagnosis ; Trisomy 13 Syndrome ; Trisomy 18 Syndrome

This study was undertaken to establish a noninvasive prenatal genetic diagnostic method for trisomy 21 using the fetal nRBCs that is rarely present in maternal circulation. Peripheral venous blood samples were collected from 30 women with an advanced maternal age, abnormal triple marker test results, or abnormal ultrasound findings such as an increased nuchal translucency. The blood samples were treated with heparin. The triple density gradient centrifugation, and MACS using CD45 and CD71 were used to isolate the fetal cells. FISH analysis using probe 21 was performed with GPA-immunostaining. The study population consisted of 30 patients from 13 to 25 weeks of gestation, and nRBCs were separated in all cases. In GPA-immuno FISH analysis using probe 21, 3 cases of trisomy 21 were diagnosed and these results were confirmed by the amniocentesis. In conclusion, a prenatal diagnosis of trisomy 21 through GPA- immuno fluorescence in situ hybridization (FISH) analysis using separated fetal nRBCs is a useful, innovative, accurate, rapid and non-invasive diagnostic method.
Adolescent ; Adult ; Down Syndrome/*diagnosis ; Female ; Human ; Immunohistochemistry ; In Situ Hybridization, Fluorescence ; Pregnancy/*blood ; Prenatal Diagnosis/*methods

Down Syndrome ; diagnosis ; Female ; Fluorescence ; Humans ; Male ; Polymerase Chain Reaction ; methods ; Pregnancy ; Prenatal Diagnosis ; methods