Development of Non-Invasive Prenatal Diagnosis for Single Gene Disorders

Cell-free fetal DNA (cffDNA) is present in the maternal blood from the early first trimester of gestation and makes up 5%-20% of the total circulating cell-free DNA (cfDNA) in maternal plasma. Its presence in maternal plasma has allowed development of noninvasive prenatal diagnosis for single-gene disorders (SGD-NIPD). This can be performed from 9 weeks of amenorrhea and offers an early, safe and accurate definitive diagnosis without the miscarriage risk associated with invasive procedures. One of the major difficulties is distinguishing fetal genotype in the high background of maternal cfDNA, which leads to several technical and analytical challenges. Besides, unlike noninvasive prenatal testing for aneuploidy, NIPD for monogenic diseases represent a smaller market opportunity, and many cases must be provided on a bespoke, patient- or disease-specific basis. As a result, implementation of SGD-NIPD remained sparse, with most testing being delivered in a research setting. The present project aims to take advantage of the unique French collaborative network to make SGD-NIPD possible for theoretically any monogenic disorder and any family.