A retrospective analysis of 8 005 cases of prenatal genetic diagnosis of thalassemia using PCR-flow fluorescence hybridization / 中华检验医学杂志

Objective:To evaluate the diagnostic capabilities of PCR-flow Fluorescence Hybridization technology in prenatal genetic diagnosis of thalassemia.Methods:8 005 cases of prenatal genetic diagnosis of thalassemia in Guangdong Women and Children Hospital from September 2017 to December 2020 were retrospectively analyzed. All samples were diagnosed by traditional genetic methods include multiple Gap-PCR, PCR-RDB, MLPA and Sanger sequencing. Meanwhile, PCR-flow Fluorescence Hybridization technology was used as a verification platform for detecting common mutation sites of thalassemia. The results were analyzed to evaluate the diagnostic capabilities of PCR-flow Fluorescence Hybridization technology compared with traditional methods in prenatal genetic diagnosis of thalassemia.Results:By traditional methods, 1 939 cases (24.22%, 1 939/8 005) were normal and 6 066 cases (75.78%, 6 066/8 005) were diagnosed as thalassemia, including 4 513 cases of α-thalassemia, 1 475 cases of β-thalassemia, and 78 cases of αβ-thalassemia. By PCR-flow Fluorescence Hybridization technology, 7 845 samples were successfully diagnosed after initial interpretation by software. Compared with traditional methods, all the sensitivity, specificity and accuracy were 100%. The other 160 samples which failed in the initial interpretation can be successfully interpreted after review or manual interpretation.Conclusion:There were no differences between the two methods on the detecting of common mutation sites of thalassemia.

Resultado de estudio prenatal invasivo para el diagnóstico de aneuploidía en el Hospital Sótero del Río / Results of an invasive prenatal study for the diagnosis of aneuploidy at Hospital Sótero del Río

ANTECEDENTES: Las aneuploidías y malformaciones congénitas son causa importante de morbi-mortalidad perinatal e infantil en Chile. OBJETIVO: Evaluar la realidad local del diagnóstico genético antenatal para mejorar el resultado perinatal. MÉTODOS: Estudio retrospectivo y descriptivo. Se realizó amniocentesis a embarazadas con indicación de estudio genético prenatal por sospecha ecográfica de alteraciones cromo-sómicas, entre octubre de 2010 y marzo de 2015, en el Hospital Sótero del Río. RESULTADOS: Los hallazgos ecográficos más frecuentes fueron: cardiopatías congénitas, malformaciones del sistema nervioso central y restricción de crecimiento fetal precoz. 164 pacientes aceptaron el estudio invasivo antenatal, obteniéndose resultados de 154. El promedio de edad materna y edad gestacional del examen fueron 30 años y 27+3 semanas, respectivamente. En embarazos con trisomía 21 y 13, el 71% de las pacientes tenía sobre 35 años. Un 31% de las muestras presentaron cariotipo anormal, siendo la más frecuente la trisomía 21 (14%), trisomía 18 (9%), monosomía X (4,5%) y trisomía 13 (2,6%). CONCLUSIÓN: El diagnóstico genético prenatal permite un adecuado manejo perinatal, coordinación apropiada entre las unidades de Obstetricia y Neonatología, y la preparación de las pacientes y sus familias para un pronóstico perinatal adverso.

BACKGROUND: Malformations and aneuploidy are a major cause of perinatal morbidity and mortality in Chile. Invasive techniques are offered to determine the fetal karyotype, when there is an abnormal finding in the ultrasound. AIMS: To assess the local situation of prenatal genetic diagnosis to improve the management of this population. METHODS: This is a retrospective and descriptive study of patients from october 2010 to march 2015, who had an amniocentesis for genetic testing due suspected fetal malformations or aneu-ploidy. RESULTS: The sonographic findings most frequently found were: congenital heart disease, malformations of the central nervous system and early growth restrictions. 164 patients agree to perform invasive prenatal genetic, obtaining 154 results. The average maternal age was 30 years and the mean gestational age at amniocentesis was 27+3 weeks. In trisomy 21 pregnancies, 71% of patients were higher than 35 years. 31% of the samples had abnormal karyotype: trisomy 21 (14%), trisomy 18 (9%), Turner's syndrome (4.5%) and trisomy 13 (3%). CONCLUSIONS: Prenatal genetic diagnosis allows appropriate perinatal management and contributes to prepare the patient and their families for an adverse perinatal outcome.

Ten-year Clinical Study of Chorionic Villus Sampling

PURPOSE: We evaluated indications for chorionic villus sampling (CVS), the positive predictive value of CVS for fetal chromosomal abnormalities, and the fetal loss rate after CVS at CHA Medical Center. MATERIALS AND METHODS: We reviewed the medical records of 511 cases of CVS performed between 67 and 120 days of gestation for prenatal cytogenetic diagnosis from April 2000 to April 2010. Fetal karyotypes were obtained by direct and indirect culture methods. RESULTS: The most common indications for CVS were abnormal ultrasonic findings including increased nuchal translucency (294/635, 46.3%). The positive predictive value of abnormal karyotyping according to indication for CVS was highest in cases with abnormal parental karyotypes (14/21, 66.7%). Mosaicism revealed by CVS comprised 3.1% of the sample (16/509). Amniocentesis revealed two cases of true mosaicism and 11 cases of confined placental mosaicism. The fetal loss rate within 4 weeks of the procedure was 1.2% (6/511). CONCLUSION: If CVS is performed by an expert clinician, it is a feasible and reliable procedure for prenatal genetic diagnosis. When CVS indicates mosaicism, the finding should be confirmed by amniocentesis to distinguish true mosaicism from confined placental mosaicism.

Prenatal genetic diagnosis and counselling: principles and clinical applications / 대한산부인과학회지

The rapid development of molecular genetic test makes it possible to screen and to diagnosis thousands of genetic diseases. Accordingly, the needs for prenatal genetic diagnosis for non-chromosomal genetic diseases are increasing. Prenatal genetic diagnosis and appropriate counselling is an important part of the overall scheme of prenatal care. Therefore, we are going to review the general principles of prenatal diagnosis and its clinical applications with several practical cases.

Chorionic Villus Sampling: Clinical and Cytogenetic Study of the First 1,058 Cases in YUMC from 1984 to 2004 years / 대한산부인과학회지

OBJECTIVE: This study was performed to evaluate the feasibility, accuracy and safety of Chorionic Villus Sampling (CVS). METHODS: We analyzed the outcome of 1,058 cases of CVS performed for prenatal genetic diagnosis between 7 and 12 weeks of gestation in the outpatient prenatal genetic clinic in Yonsei University Medical Center (1,030 cases by trans-cervical method and 28 cases by trans-abdominal). Fetal Karyotyping was obtained by direct or indirect culture methods using Gimsa and Gimsa-Banding. RESULTS: Advanced maternal age was the most common indication for CVS (34.7%). The overall sampling success rate was 98% (1040/ 1,058), representing 92.5% in 7 to 8 weeks, 98.0% in 9 to 10 weeks, and 98.9% in 11 to 12weeks of gestation. The majority of cases (94.6%) required one or two aspirations. Cytogenetic analysis routinely included direct overnight and long-term culture methods, which revealed 27 chromosomal abnormalities (2.6%). Of 1,040 cases in which CVS were successful, 989 delivered normal baby, 23 resulted in fetal loss, 25 had therapeutic termination (24 with chromosome abnormalities and 1 with normal chromosome with huge myoma), and 3 with chromosome abnormalities were loss to follow up. The overall fetal loss rate was 2.2% (23/1,058). No congenital anomalies were found to be related to CVS in these series. CONCLUSION: When performed by experienced operators and cytogeneticists beyond 9 weeks of gestation, CVS is a feasible, accurate and safe method for prenatal genetic diagnosis capable of replacing genetic amniocentesis.

Prenatal Aneuploidy Detection in Uncultured Amniotic Fluid Interphase Cells by Fluorescence in situ Hybridization (FISH) / 대한불임학회지

OBJECTIVE: The aim of the present study was to evaluate the clinical efficiency of fluorescent in situ hybridization (FISH) in the prenatal diagnosis of chromosomal aneuploidy. METHODS: We reviewed data of 268 cases to identify women undergoing genetic amniocentesis at cytogenetic laboratory, from January 2000 to December 2002. Amniotic fluid was submitted for both rapid FISH on uncultured interphase amniocytes using a commercially available DNA probe for chromosome 13, 18, 21, X, Y and standard karyotyping on cultured metaphase amniocytes. Results from FISH and full karyotype were compared. RESULTS: There were 251 cases (84%) normal and 17 cases (16%) abnormal in FISH results. All 17 cases of trisomy 13, 18, 21 including two cases of mosaicism and sex chromosome aneuploidies which are detected by FISH were confirmed with conventional cytogenetics and there was no false positive result. Twenty two cases had karyotypically proven abnormalities that could not have been detected by the targeted FISH. CONCLUSION: Interphase FISH analysis of uncultured amniotic fluid cells has been shown to be an effective and reliable technique for rapid fetal aneuploidy screening during pregnancy as an adjunctive test to conventional cytogenetics.