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.
Study Type
OBSERVATIONAL
Enrollment
830
Nancy University Hospital
Nancy, France
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)
Time frame: baseline
Type of ultrasound call sign
The ultrasound signs will be defined by the ultrasound technician thanks to the recommended classification
Time frame: 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
Time frame: 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.).
Time frame: baseline
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