Comparison of Two NGS Phasing Techniques of Parental Haplotypes for NIPD of Triplet Expansion Diseases
试验速览
- 阶段
- 不适用
- 入组人数
- 36
- 试验地点
- 1
- 主要终点
- Concordance rate between cell free foetal DNA based genetic
研究概览
简要总结
The purprose of this study is to develop and validate an analytical NIPD test for triplet repeat disesases by NGS analysis from maternal blood, searching for the familial mutation in families at risk of having one of the following triplet repeat diseases: Huntington's disease, Myotonic dystrophy, Fragile X syndrome.. A comparison of two 3rd generation long fragment DNA sequencing techniques will be performed. These methods are based of the phasing techniques of parental haplotypes without the proband.
详细描述
Context:
The ability to sequence fetal cfDNA has led to exciting new developments for the non-invasive genetic diagnosis of monogenic diseases (DPNI_MGR). Various tests are proposed for diseases with predominantly de novo dominant, dominant paternal and some recessive paternal mutations. However, technical difficulties related to the determination of the maternal allelic balance remain, in particular during the phasing of parental haplotypes according to a trio strategy which requires the availability of parental genomic DNAs and at least one healthy or affected child. Moreover 2nd generation sequencers do not allow the haplotyping of alleles carrying dynamic mutations.
Objectives:
This project proposes the validation of a semi-universal DPNI_MGR test applicable to the majority of the genes and mutations involved in DPN requests from phasing of parental haplotypes by 3rd generation long-fragment DNA sequencing techniques coupled with targeted sequencing of free circulating DNA from maternal plasma. This test will be validated using triplet expansion diseases, which are the second indication of DPN at the national level.
Methodology :
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Retrospective
入排标准
- 年龄范围
- 18 Months 至 —（Child, Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- 未提供
排除标准
- 未提供
结局指标
主要结局
Concordance rate between cell free foetal DNA based genetic
时间窗: 36 months
t is a qualitative analysis : for each sample of each pregnant women, the presence of absence of a mutation (or morbid haplotype) responsible for a triplet expansion will be determined from maternal blood (Non invasive Pregnancy Diagnosis). the result could be : health fetus, affected fetus or non conclusive result (i.e. the analysis didn't allow to conclude if the fetus would be affected or not) Then, determination of the concordance rate between cell-based genetic non invasive prenatal test and gold standard prenatal test (choriocentesis or amniocentesis). Analysis of the concordance of the prenatal results obtained by our new NIPD (Non-Invasive Prenatal Diagnosis) approach and those blindly obtained during the gold-standard prenatal genetic test will be carried out for each pregnant woman participating in the study
次要结局
- Qualitative process to define the differents steps to analysis of the cell free foetal DNA(36 months)