Evaluation of the Relevance of Comparative Genomic Hybridization in Prenatal Diagnosis

Study Overview
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Brief Summary
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Pre-natal diagnosis is developing nowadays thanks to the improvement of ultrasound performances but also of genetic analysis techniques. The karyotype was previously the reference technique for genetic analysis. The development of comparative genomic hybridization, consisting of comparative genomic hybridization on DNA sequences and allowing the diagnosis of unbalanced chromosomal rearrangements, has made it possible to increase the resolution threshold for the detection of genetic anomalies. This technique can be performed both pre and post natal. In pre-natal, the indications for this genetic study are based on ultrasound signs and are regularly updated in the international literature. Due to the complete analysis of the genome and the increase of the resolution threshold, genetic anomalies not related to the detected ultrasound pathology may be discovered and may pose ethical problems from a genetic counseling point of view. To date, the diagnostic performance of comparative genomic hybridization as a complement to karyotype is being confirmed and needs to be clarified in order to limit the risk of incidental discovery of genetic anomalies whose significance remains unknown. Through the study that the investigator would like to carry out, the investigator seek to evaluate the diagnostic contribution of this comparative genomic hybridization technique compared to the data provided by the karyotype according to the various ultrasound call signs on the Nancy cohort of files presented to the multidisciplinary pre-natal diagnosis committee, since the launch of the comparative genomic hybridization in Nancy in 2012 until 2018.

Official Title
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Evaluation of the Contribution of Comparative Genomic Hybridization Compared to Karyotype for the Detection of Genetic Abnormalities According to Ultrasound Call Signs in Prenatal Screening: the Cohort of the Nancy Multidisciplinary Center for Prenatal Diagnosis From 2012 to 2018

Conditions
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Comparative Genomic Hybridization

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: CGH-array performed for ultrasound findings at the genetic laboratory of the Nancy University Hospital from 01/10/2012 to 31/12/2018 Results of the CGH-array presented to the multidisciplinary pre-natal diagnosis committee of Nancy Exclusion Criteria: patients who objected to the use of their data for research purposes when signing the informed consent form given during the genetic consultation
Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CGH-array abnormality | An anomaly will be detected at CGH-array if its size is greater than or equal to 500 Kb. Size of these anomalies will be considered in a binary manner: < 10 Mb (i.e. not visible on karyotype) and ≥ 10 Mb (i.e. visible on karyotype) | baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Type of ultrasound call sign | The ultrasound signs will be defined by the ultrasound technician thanks to the recommended classification | baseline | 
| Genotype-phenotype concordance | The genotype-phenotype concordance is defined by the cytogeneticist who delivers the results, according to the current scientific knowledge described in the literature | baseline | 
| Particular gravity | The particular gravity (Yes/No) of the ultrasound sign is defined after consultation between the various health professionals gathered at the multidisciplinary pre-natal diagnosis committee (gynaecologist, paediatrician, geneticist, radiologist, histopathologists, surgeons, etc.). | baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Prenatal diagnosis, Ultrasound sign