Maternal UPD of chromosome 7 is associated with pre- and postnatal growth retardation (IUGR, PNGR) and Silver-Russell syndrome (SRS [MIM 180860]). We report a case of IUGR in a newborn with SRS stigmata. Using combined haplotyping and cytogenetic-FISH studies we characterized the lymphocytes, umbilical cord and four placental cotyledons. The results are consistent with complete maternal isodisomy 7 and trisomy 7 mosaicism of post-zygotic origin. The trisomic cell line was prevalent in trophoblast cells from two placental cotyledons. Trisomy 7 of post-zygotic origin is a frequent finding, but maternal isodisomy 7, due to trisomic rescue has never been reported. PEG1/MEST expression was evaluated on placenta cDNA and a specific transcript was revealed only in the cotyledons with a high percentage of trisomic cells and the presence of the paternal chromosome 7 contribution, but not in the placental biopsies with maternal isodisomy 7. The histological features of the four placental fragments revealed that isodisomy 7 correlates with a pattern of cotyledonary hyper-ramification due to an increase of the branching angiogenesis, which could be the result of a defect of angiogenesis caused by the absence of PEG1 product. The severe hypo-ramification of the two cotyledons, showing trisomy 7 mosaicism, may be due to the triplicate dosage of genes on chromosome 7. The delayed fetal growth could be the phenotypic effect of the imbalance between imprinted and non-imprinted genes on chromosome 7 in the fetus or the result of abnormal placental function during pregnancy.
Post-zygotic origin of complete maternal chromosome 7 isodisomy and consequent loss of placental PEG1/MEST expression / M. Miozzo, F. R. Grati, G. Bulfamante, F. Rossella, M. Cribiù, T. Radaelli, B. Cassani, T. Persico, I. Cetin, G. Pardi, G. Simoni. - In: PLACENTA. - ISSN 0143-4004. - 22:10(2001 Nov), pp. 813-821.
|Titolo:||Post-zygotic origin of complete maternal chromosome 7 isodisomy and consequent loss of placental PEG1/MEST expression|
MIOZZO, MONICA ROSA (Primo)
GRATI, FRANCESCA ROMANA (Secondo)
PARDI, GIORGIO (Penultimo)
|Parole Chiave:||Uniparental Disomy; Cytogenetic Analysis; Chorionic Villi; Humans; Gestational Age; Gene Expression; In Situ Hybridization, Fluorescence; Infant, Newborn; Lymphocytes; Chromosomes, Human, Pair 7; Pregnancy; Haplotypes; Placenta; Adult; DNA; Proteins; Male; Female; Fetal Growth Retardation|
|Settore Scientifico Disciplinare:||Settore MED/40 - Ginecologia e Ostetricia|
|Data di pubblicazione:||nov-2001|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1053/plac.2001.0728|
|Appare nelle tipologie:||01 - Articolo su periodico|