Pediatric severe factor XI deficiency: A multicenter study.

Background: Factor XI (FXI) deficiency is a rare autosomal recessive bleeding disorder. Only scarce publications address its clinical features in children. The increased prevalence of FXI deficiency in Israel enabled data collection for this large multicenter cohort study.

A man-made disease: Fetal neonatal alloimmune thrombocytopenia due to incompatibility between oocyte donor and gestational mother.

The incompatibility causing fetal and neonatal alloimmune thrombocytopenia (FNAIT) results from a fetus inheriting a paternal human platelet antigen (HPA), which is different from the maternal HPA. We present a unique case of FNAIT in a pregnancy involving an oocyte recipient mother with Turner syndrome. This is the first report of FNAIT in which the suggested mechanism involves antibodies produced by a gestational mother against the incompatible HPA of the oocyte donor.