Feasibility for non‐invasive prenatal fetal blood group and platelet genotyping by massively parallel sequencing: A single test system for multiple atypical red cell, platelet and quality control markers

Abstract

SummaryNon‐invasive prenatal tests (NIPT) to predict fetal red cell or platelet antigen status for alloimmunised women are provided for select antigens. This study reports on massively parallel sequencing (MPS) using a red cell and platelet probe panel targeting multiple nucleotide variants, plus individual identification single nucleotide polymorphisms (IISNPs). Maternal blood samples were provided from 33 alloimmunised cases, including seven with two red cell antibodies. Cell‐free and genomic DNA was sequenced using targeted MPS and bioinformatically analysed using low‐frequency variant detection. The resulting maternal genomic DNA allele frequency was subtracted from the cell‐free DNA counterpart. Outcomes were matched against validated phenotyping/genotyping methods, where available. A 2.5% subtractive allele frequency threshold was set after comparing MPS predictions for K, RhC/c, RhE/e and Fya/Fyb against expected outcomes. This threshold was used for subsequent predictions, including HPA‐15a, Jka/Jkb, Kpa/Kpb and Lua. MPS outcomes were 97.2% concordant with validated methods; one RhC case was discordantly negative and lacked IISNPs. IISNPs were informative for 30/33 cases as controls. NIPT MPS is feasible for fetal blood group genotyping and covers multiple blood groups and control targets in a single test. Noting caution for the Rh system, this has the potential to provide a personalised service for alloimmunised women.

Non-invasive prenatal test identifies circulating cell-free DNA chromosomal abnormalities derived from clonal hematopoiesis in aggressive hematological malignancies

“…Whole exome or genome sequencing evaluate all mutations or the entire tumor genome with the ability to identify deleterious alterations, variants of unknown significance, or novel variants; however, they are not routinarly used in clinical practice [ 36 ]. NIPT is a methodology employed for minimally invasive analysis of fetal DNA in maternal circulation with the purpose to identify fetal chromosomal abnormalities before birth, by avoiding invasive diagnostic tests [ 37 ]. Recently, it has been described that positive NIPT in the absence of fetal chromosomal alterations confirmed by amniocentesis or chorionic villus sampling can be an alert for maternal unknown silent cancers [ 23 ].…”