Application of SNP array for rapid prenatal diagnosis - implementation, genetic counselling and diagnostic flow

Malgorzata Ilona Srebniak (1) , Marjan Boter (1) , Gretel G Oudesluijs (1) , Marieke Joosten (1) , Lutgarde C.P. Govaerts (1) , Diane van Opstal (1) , Robert-Jan H. Galjaard (1)

1 Department of Clinical Genetics

We report on the validation and implementation of the HumanCytoSNP-12 array (Illumina) (HCS) in prenatal diagnosis. 64 samples were used to validate the Illumina platform (20 with a known (sub) microscopic chromosome abnormality, 5 with known maternal cell contamination and 39 normal control samples). There were no false positive or false negative results. In addition to the diagnostic possibilities of arrayCGH, the HCS allows detection of regions of homozygosity (ROH), triploidy and helps recognizing maternal cell contamination (MCC). Moreover, in 2 cases of maternal cell contamination, a deletion was correctly detected. Furthermore we found out that only about 50 ng of DNA is required, which allows a reporting time of only 3 days. We also present a prospective pilot study of 61 foetuses with ultrasound abnormalities and a normal karyotype tested with HCS. In 4/61 (6,5%) foetuses a clinical relevant abnormality was detected. We designed and present pre-test genetic counselling information on categories of possible test outcomes. On the basis of this information about 90% of the parents chose to be informed about adverse health outcomes of their future child at infancy and childhood and 55% also about outcomes at an adult stage. The latter issue concerning the right of the future child itself to decide whether or not to know this information needs to be addressed.

Mots clés: genomic SNP array; pre-test counselling; prenatal diagnosis

Malgorzata Ilona Srebniak, Marjan Boter, Gretel G Oudesluijs, Marieke Joosten, Lutgarde C.P. Govaerts, et al.. Application of SNP array for rapid prenatal diagnosis - implementation, genetic counselling and diagnostic flow. European Journal of Human Genetics, 2011, ⟨10.1038/ejhg.2011.119⟩. ⟨hal-00654468⟩