Meiotic origin of trisomy in confined placental mosaicism is correlated with presence of fetal uniparental disomy, high levels of trisomy in trophoblast, and increased risk of fetal intrauterine growth restriction.
- 1 April 1997
- journal article
- Vol. 60 (4) , 917-27
Abstract
Molecular studies were performed on 101 cases of confined placental mosaicism (CPM) involving autosomal trisomy. The origin of the trisomic cell line was determined in 54 cases (from 51 pregnancies), 47 of which were also analyzed for the presence of uniparental disomy (UPD) in the disomic cell line. An additional 47 cases were analyzed for parental origin in the disomic cell line only. A somatic (postmeiotic) origin of the trisomy was observed in 22 cases and included the majority of cases with CPM for trisomy 2, 7, 8, 10, and 12. Most cases of CPM involving trisomy 9, 16, and 22 were determined to be meiotic. Fetal maternal UPD was found in 17 of 94 informative CPM cases, involving trisomy 2 (1 case), 7 (1 case), 16 (13 cases), and 22 (2 cases). The placental trisomy was of meiotic origin in all 17 cases associated with fetal UPD (P = .00005). A meiotic origin also correlated with the levels of trisomy in cultured chorionic villi samples (CVS) (P = .0002) and trophoblast (P = .00005). Abnormal pregnancy outcome (usually IUGR) correlated with meiotic origin (P = .0003), the presence of fetal UPD (P = 4 x 10(-7)), and the level of trisomy in trophoblast (P = 3 x 10(-7)) but not with the level of trisomy in CVS or term chorion. The good fit of somatic errors with the expected results could have been observed only if few true meiotic errors were misclassified by these methods as a somatic error. These data indicate that molecular determination of origin is a useful predictor of pregnancy outcome, whereas the level of trisomy observed in cultured CVS is not. In addition, UPD for some chromosomes may affect prenatal, but not postnatal, development, possibly indicating that imprinting effects for these chromosomes are confined to placental tissues.This publication has 30 references indexed in Scilit:
- Molecular studies of chromosomal mosaicism: relative frequency of chromosome gain or loss and possible role of cell selection.1995
- Nondisjunction of human acrocentric chromosomes: studies of 432 trisomic fetuses and livebornsHuman Genetics, 1994
- Uniparental isodisomy for paternal 7p and maternal 7q in a child with growth retardation.1994
- A somatic origin of homologous Robertsonian translocations and isochromosomes.1994
- Maternal uniparental disomy 22 has no impact on the phenotype.1994
- Confined Placental Mosaicism and StillbirthPediatric Pathology, 1994
- Nondisjunction of chromosome 15: origin and recombination.1993
- Mosaicism in chorionic villus sampling: An analysis of incidence and chromosomes involved in 2612 consecutive casesPrenatal Diagnosis, 1993
- Uniparental disomy for chromosome 16 in humans.1993
- Trisomy 15 with loss of the paternal 15 as a cause of Prader-Willi syndrome due to maternal disomy.1992