Complete hydatidiform mole retaining a chromosome 11 of maternal origin: molecular genetic analysis of a case.
Hydatidiform moles are pregnancies characterized by abnormal development of both embryonic and extraembryonic tissues and are associated with the misexpression of imprinted genes. The vast majority of complete hydatidiform moles are diploid and androgenetic, whereas partial hydatidiform moles are triploid, with an extra set of chromosomes of paternal origin. Here, we present an unusual complete mole that showed strong expression of two imprinted, maternally transcribed genes, CDKN1C (encoding p57(KIP2)) and PHLDA2 (TSSC3/IPL), both part of a large imprinted gene domain on chromosome 11. Using microsatellite genotyping and fluorescent in situ hybridization, we show that this paradoxical gene expression was due to retention of a maternal copy of chromosome 11 in addition to the two paternal copies normally present in complete moles. These findings demonstrate that, despite being predominantly androgenetic, some complete moles contain small amounts of DNA of maternal origin. Furthermore, these results provide an explanation for rare false negatives that can arise when p57(KIP2) is used as a diagnostic marker for complete moles.
Department of Cancer Medicine, Faculty of Medicine, Imperial College London, Charing Cross Hospital, London, UK.
Rosemary A
RA
Fisher
Marisa R
MR
Nucci
Harshwardhan M
HM
Thaker
Stanislawa
S
Weremowicz
David R
DR
Genest
Diego H
DH
Castrillon
D000328:Adult; D002869:Chromosome Aberrations; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D050761:Cyclin-Dependent Kinase Inhibitor p57; D005260:Female; D006801:Humans; D006828:Hydatidiform Mole / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D018895:Microsatellite Repeats; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics; D011247:Pregnancy; D014594:Uterine Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*
C493964:CDKN1C protein, human; D050761:Cyclin-Dependent Kinase Inhibitor p57; D009687:Nuclear Proteins