Prospective Prenatal Diagnosis of Prader–Willi Syndrome due to Maternal Disomy for Chromosome 15 following Trisomic Zygote Rescue

From Prader–Willi Syndrome to Psychosis: Translating Parent-of-Origin Effects into Schizophrenia Research

“…In turn, mUPD may be formed by trisomic rescue of trisomic conception, monosomy rescue and post fertilization errors with the loss of the paternal chromosome 15 and can be inferred from the pattern of uniparental hetero or isodisomy [21]. Rarely, the trisomy persists in live-born infants also as the tissue-limited mosaicism and in most cases is the reason of the early spontaneous abortion [22]. An example of possible mosaicisms of UPD and other aberrations are two PWS patients described by Izumi et al [21].…”

Retrospective diagnosis of trisomy 15 in formalin-fixed, paraffin-embedded placental tissue in a newborn girl with Prader-Willi syndrome

“…Fertilization of an oocyte disomic for chromosome 15 by a monosomic sperm for chromosome 15 with somatic loss of the paternally inherited chromosome 15 is one possible mechanism. This hypothesis is supported by previously reported cases where a trisomy 15 had been detected in chorionic villus sampling (CVS) and follow-up amniocentesis revealed normal karyotypes (Cassidy et al, 1992;Purvis-Smith et al, 1992, Roberts et al, 1997. Another mechanism, proposed by Engel (1980), is the fertilization of a chromosome 15 disomic oocyte by a sperm nullisomic for chromosome 15.…”

Trisomy 15 CPM: probable origins, pregnancy outcome and risk of fetal UPD

“…Some adjustment would be required to make a true population estimate, because of the maternal age bias in CVS. The very high estimate of trisomy 15 CPM of 80/100 000 CVS calculated by Robinson et al (1996) on the basis of cases from the literature Roberts et al (1997). h Published in Schulze et al (1986).…”