A One-Step Real-Time PCR Assay for Rapid Prenatal Diagnosis of Sickle Cell Disease and Detection of Maternal Contamination

2003 ◽  
Vol 7 (1) ◽  
pp. 45-48 ◽  
Author(s):  
Catherine Costa ◽  
Serge Pissard ◽  
Emmanuelle Girodon ◽  
Danièle Huot ◽  
Michel Goossens
Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2133-2133 ◽  
Author(s):  
Antonino Giambona ◽  
Gianfranca Damiani ◽  
Filippo Leto ◽  
Cristina Yakil ◽  
Cristina Passarello ◽  
...  

Abstract In countries with a high prevalence of hemoglobinopathy carriers, the only realistic approach to control the birth of new patients with thalassemia major or sickle cell disease is population screening in combination with invasive prenatal diagnosis[1]. In the early 1990's, molecular definition of the thalassemia defects, development of procedures for their detection by DNA analysis and introduction of amniotic fluid sampling (amniocentesis) or chorionic villus sampling (CVS) led to early prenatal diagnosis at 16 and 11 weeks, respectively [2]. An alternative technique for earlier diagnosis is celocentesis [3]. At the end of week 4 of gestation, the developing exocoelomic cavity (ECC) splits the extra-embryonic mesoderm into two layers, the somatic mesoderm lining the trophoblast and the splanchnic mesoderm covering the secondary yolk sac and the embryo. The ECC is the largest anatomical space inside the gestational sac between 5 and 9 weeks of gestation and is surrounded by celomic fluid (CF), which contains cells of fetal origin [4-5]. This fluid can be sampled by a technique that involves the ultrasound-guided insertion of a needle through the vagina from as early as 7 weeks of gestation. Previous studies utilizing coelocentesis for prenatal determination of single-gene defects reported variable success ranging from 58 to 95% because of presence of maternal cell contamination (MCC) [6]. In this work we demostred as this problem can be overcome through the identification of embryo-fetal erythroid precursors presented in the coelomatic fluid and their specific selection. 302 couples from different regions of Italy, at risk for ß thalassemia or sickle cell disease asked for prenatal diagnosis by coelocentesis that was carried out at between 6+6 and 9+2 weeks' gestation. Coelomic fluid samples with no or very low (<5%) maternal contamination (100 samples) were successfully analyzed without preliminary treatment. In samples with >5% maternal contamination, two different procedures were used to isolate embryo-fetal cells: the first technique involved positive selection of embryo-fetal erythroid precursors by anti-CD71 MicroBeads (160 samples), the second procedure was through the use of a micromanipulator (42 samples). In 68/300 (22.6%) cases the fetus was affected by ß-thalass/ß-thalassemia and 66 women chosen to terminate the pregnancy. Two families decided to continue the pregnancy for ethical reasons despite the documented presence of an affected fetus. The antenatal diagnosis was confirmed in all 66 cases by molecular analysis of placental tissue after termination (Table 1). In 232/300 (77.4%) cases the fetus was diagnosed as being normal or a carrier for ß-thalassemia or sicke cell disease. The results obtained after coelocentesis were confirmed by amniocentesis or postnatally. In two case (0.66%) was no obtained a reliable diagnosis because no fetal cells were found (Table 1). The findings of this study in a large number of pregnancies investigated by coelocentesis, demonstrate that embryo-fetal erytroid cell selection from coelomatic fluid allows reliable and earlier prenatal diagnosis of hemoglobinopathies. This technique is attractive to parents because it provides prenatal diagnosis of genetic disease at least 4 weeks earlier respect to traditional procedures reducing anxiety of parents and from a clinical point of view this procedure would allow women to undergo medical TOP at 8-10 weeks of gestation which is less traumatic and safer than second trimester surgical TOP. Table 1. Overall results of prenatal diagnosis of hemoglobinopathies by coelocentesis. Number of coelocentesis effectuated 302 Results of Prenatal diagnosis: Affected 68 Carrier of hemoglobinopathies 161 Non Affected 71 diagnosis not reiable 2 Control post coelocentesis: Placental tissue after termination 66 CVS or amniocentesis 153 Postnatal test 61 Awaiting 20 Coelocentesis diagnostic errors 0 Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2085-2085
Author(s):  
Yvonne Daniel ◽  
Julia Van Campen ◽  
Lee Silcock ◽  
Michael Yau ◽  
Joo Wook Ahn ◽  
...  

Sickle cell disease (SCD) is the most common genetic haematological disorder worldwide. Around 300.000 affected infants are born every year, including at least 1000 in the United States. Prenatal diagnosis is currently carried out using amniotic fluid or chorionic villus sampling. These invasive procedures are perceived to have a small risk of miscarriage. The availability of non-invasive prenatal diagnosis (NIPD) is predicted to increase uptake of prenatal diagnosis for SCD, as it has no perceived miscarriage risk. NIPD may also be more readily implemented than invasive prenatal diagnosis in the low-resource countries in which SCD is the most prevalent. However, accurate NIPD of autosomal recessive disorders such as sickle cell disease has proven challenging as this requires detection of fetal inheritance of a maternal allele from a mixed maternal-fetal pool of cell-free DNA. We report the development of a targeted massively parallel sequencing assay for the NIPD of fetal SCD using cell-free fetal DNA from maternal plasma. No paternal or previous offspring samples were required. 44 clinical samples were analysed, including 37 plasma samples from pregnant SCD carriers and 7 plasma samples from women with SCD due to Hb SC. We used a relative mutation dosage based approach for the 37 samples from maternal SCD carriers (Hb AS or Hb AC), integrating Unique Molecular Identifiers (UMIs) into the analysis to improve the accuracy of wildtype and mutant allele counts. We used a separate wildtype allele detection approach for the 7 samples from women with compound heterozygous SCD, in whom the detection of wildtype cell-free DNA indicates the presence of a carrier fetus. The success of the assay was evaluated by comparing results with the established fetal sickle status as determined through either invasive prenatal diagnosis or newborn screening. During development, two key factors improved the accuracy of the results: i) Selective analysis of only smaller cell-free DNA fragments enhanced the fetal fraction for all samples, with greater effects observed in samples from earlier gestations. This approach improved diagnostic accuracy: for 3 out of 44 samples, the genotype was inconclusive or incorrect before size selection, but correct after size selection. ii) Modifications to DNA fragment hybridisation capture optimised the diversity of Unique Molecular Identifier-tagged molecules analysed. This led to improvements in the results obtained for 5 samples, with 3 previously inconclusive samples correctly called and 2 previously discrepant results moved into the inconclusive range. In total, 37 results were concordant with the established fetal sickle status; this included 30/37 samples from carrier women and 7/7 samples from women with sickle cell disease due to Hb SC. The remaining 7 carrier samples gave an inconclusive result, which for 3 samples was attributed to a low fetal fraction. Samples from as early as 8 weeks gestation were successfully genotyped. There were no false positive or false negative results. This study is the largest to use NGS-based NIPD on clinical plasma samples from pregnancies at risk of SCD. Efforts to validate the assay on a larger sample cohort and to reduce the inconclusive rate are warranted. This study shows that NIPD for SCD is approaching clinical utility and has the potential to provide increased choice to women with pregnancies at risk of sickle cell disease. Disclosures Silcock: Nonacus Ltd.: Employment.


2010 ◽  
Vol 12 (1) ◽  
pp. 102-108 ◽  
Author(s):  
Duc H. Do ◽  
Stella Laus ◽  
Amy Leber ◽  
Mario J. Marcon ◽  
Jeanne A. Jordan ◽  
...  

2018 ◽  
Vol 22 (5) ◽  
pp. 418-423
Author(s):  
Elisabete Andrade ◽  
Daniele Rocha ◽  
Marcela Fontana-Maurell ◽  
Elaine Costa ◽  
Marisa Ribeiro ◽  
...  

2018 ◽  
Vol 140 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Zhara A. Al-Ali ◽  
Rana K. Fallatah ◽  
Esra A. Aljaffer ◽  
Eman R. Albukhari ◽  
Neriman Sadek Al-Ali ◽  
...  

Disease severity of sickle cell anemia is highly variable, and it is commonly accepted that fetal hemoglobin (HbF) levels play a major role as an ameliorating factor. Investigation of genetic variants have identified several genes to be the principal influencers of HbF regulation. Here, we further elucidated the association of rs4527238 and rs35685045 of ANTXR1 genes in the context of HbF level variance in sickle cell anemia patients of the Arab-Indian haplotype. Samples from 630 sickle cell anemia patients were analyzed for the mutations at 2 specific locations of the ANTXR1 gene by TaqMan®-based real-time PCR. The CC genotype (p = 0.018) of rs4527238 and the TT genotype (p = 0.048) of rs35685045 of ANTXR1 were found to be significantly associated with low HbF expression. The frequency of the CC genotype of rs4527238 was observed to be high in the low HbF patient group compared to the high HbF group (p = 0.009). Likewise, the frequency of the TT genotype of rs35685045 was also high among the low HbF group (p = 0.017). The ANTXR1 genetic mutations and the association with HbF expression in the Arab-Indian haplotype sickle cell patients revealed that the ANTXR1 gene may be a major HbF modulator leading to potential therapeutic options that should be further explored.


2006 ◽  
Vol 316 (1-2) ◽  
pp. 125-132 ◽  
Author(s):  
Nils Reinton ◽  
Asle Helgheim ◽  
Hamid Shegarfi ◽  
Amir Moghaddam

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1371-1371
Author(s):  
Nathaniel Z. Piety ◽  
Xiaoxi Yang ◽  
Bogdan R. Dinu ◽  
Alex George ◽  
Sergey S. Shevkoplyas

Abstract Introduction: Sickle cell disease (SCD) is a common inherited blood disorder caused by sickle hemoglobin (HbS) which, unlike normal adult hemoglobin (HbA), becomes insoluble and polymerizes under hypoxic conditions. Patients with SCD experience chronic hemolytic anemia, episodic pain crises and abnormal blood flow to critical organs that cumulatively result in significant illness and shortened lifespans for many. The severity of SCD varies significantly between patients, but for individuals the rate of adverse events is strongly correlated with intraerythrocytic concentration of HbS (%HbS). High per test costs and long turnaround times make conventional laboratory methods (e.g. Hb electrophoresis, HPLC, IEF) impractical for quantifying %HbS in real-time (e.g. during transfusion therapy). The objective of this study was to demonstrate that %HbS in blood could be quantified using our recently developed rapid, low-cost paper-based SCD assay [1]. Methods: Blood samples were obtained from SCD and sickle cell trait (SCT) patients at the Texas Children’s Hematology Center (Houston, TX). To perform the SCD assay a 20μL droplet of blood mixed with Hb solubility buffer (1:10 by volume) was dropped on chromatography paper. The resulting blood stain was digitized with a flatbed scanner (Canon USA Inc, Melville, NY) and analyzed using a custom image analysis code (The MathWorks Inc, Natick, MA). Conventional Hb electrophoresis was performed with the semi-automated Sebia Hydrasys 2 Scan system (Sebia Inc, Norcross, GA). Results: The difference in transport of Hb through the paper produced a blood stain with two parts: the area of the initial drop where polymerized HbS is retained (center spot) and the area where soluble Hb is wicked laterally (peripheral ring). The relative color intensity of the center spot and peripheral ring is related to the blood sample %HbS (Fig. 1). The image analysis code automatically isolates and calculates the ratio of the average color intensities of each area (S-index). A series of reconstituted blood samples with artificially adjusted %HbS from 0 to 60% was used to calibrate the assay so that %HbS could be estimated based on blood stain color intensities (Fig. 2a). The values of %HbS estimated for patient samples using our paper-based SCD assay and actual values measured using conventional Hb electrophoresis were highly correlated with R2 = 0.898 (Fig. 2b). The estimated and actual %HbS values also showed strong agreement with the standard deviation of the difference between the two measurements = 5.5 %HbS (Fig. 2c). The majority of the differences between actual and estimated %HbS (96.67%) are within 2 standard deviations of the mean of the differences. The assay could be performed in under 35 minutes and multiple assays could be performed and analyzed in parallel. The cost of consumable materials and reagents for the paper-based SCD assay is less than $0.03. Conclusions: This study demonstrates the feasibility of using our recently developed paper-based assay to quantify %HbS in blood samples in real-time. The ability to rapidly, inexpensively measure %HbS will be particularly useful for monitoring the effectiveness of chronic transfusion or hydroxyurea therapy for long-term control of HbS content in blood of SCD patients. The ability to measure %HbS in real-time could also potentially facilitate more aggressive prophylactic therapy to intervene rapidly and significantly reduce the rate of life-threatening complications in SCD patients, including stroke. Figure 1: Figure 1:. Figure 2: Figure 2:. Acknowledgments: This work was supported in part by a 2012 NIH Director's Transformative Research Award (NHLBI R01HL117329, PI: SSS). References: [1] Yang X, et al. Lab Chip, 2013, 13, 1464-1467. Disclosures Piety: Tulane University: PCT/US2012/064856 Patents & Royalties. Yang:Tulane University: PCT/US2012/064856 Patents & Royalties. Shevkoplyas:Tulane University: PCT/US2012/064856 Patents & Royalties; Halcyon Biomedical Incorporated: Equity Ownership.


2014 ◽  
Vol 196 ◽  
pp. 145-151 ◽  
Author(s):  
Wei Jiang ◽  
Ping-zhong Wang ◽  
Hai-tao Yu ◽  
Ye Zhang ◽  
Ke Zhao ◽  
...  

2019 ◽  
Author(s):  
Anjelica C Saulsberry ◽  
Jason R Hodges ◽  
Audrey Cole ◽  
Jerlym S Porter ◽  
Jane Hankins

BACKGROUND Advancements in treatment have contributed to increased survivorship among children with sickle cell disease (SCD). Increased transition readiness, encompassing disease knowledge and self-management skills before transfer to adult care, is necessary to ensure optimal health outcomes. The Sickle Cell Transition E-Learning Program (STEP) is a public, Web-based, 6-module tool designed to increase transition readiness for youth with SCD. OBJECTIVE The objective of our study was to investigate the participation rate of youth with SCD in STEP and its association with transition readiness. METHODS This was a single-center, Institution Review Board–approved, retrospective cohort review. A total of 183 youths with SCD, aged between 12 and 15 years, were offered STEP as an adjunct to in-clinic disease education sessions. Participation rate (number of patients who used at least one STEP module divided by those approached) was calculated. The association among the number of STEP modules completed, disease knowledge, and self-management was explored. RESULTS Overall, 53 of the 183 approached adolescents completed at least one STEP module, yielding a participation rate in STEP of 29.0%. Of the 53 participants, 37 and 39 adolescents had disease knowledge and self-management confidence rating available, respectively. A positive correlation (<italic>r</italic>=0.47) was found between the number of STEP modules completed and disease knowledge scores (<italic>P</italic>=.003). No association was found between the number of modules completed and self-management confidence ratings. Disease knowledge scores were significantly higher among participants who completed ≥3 STEP modules compared with those who completed &lt;3 STEP modules (<italic>U</italic>=149.00; <italic>P</italic>=.007). CONCLUSIONS Improvement in disease knowledge in adolescence is critical to ensure the youth’s ability to self-care during the period of transition to adult care. Despite low participation, the cumulative exposure to the STEP program suggested greater promotion of disease knowledge among adolescents with SCD before transfer to adult care.


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