Maternal alleles acquiring paternal methylation patterns in biparental complete hydatidiform moles.
We previously mapped a maternal locus responsible for biparental complete hydatidiform moles (BiCHMs) to 19q13.4. The two index patients had a total of 14 molar pregnancies, eight abortions at various developmental stages, and one 16-year-old healthy offspring. We suggested that the defective gene deregulates the expression of imprinted genes. Here, we report the methylation status of four imprinted genes in two BiCHMs from the two sisters, the 16-year-old normal offspring, and two sporadic BiCHMs from unrelated patients. Using two bisulfite-based methods, we demonstrate a general trend of abnormal hypomethylation at the paternally expressed genes, PEG3 and SNRPN, and hypermethylation at the maternally expressed genes, NESP55 and H19, in two to four BiCHMs. Using single nucleotide polymorphisms, we provide the first evidence that SNRPN, NESP55 and H19 are abnormally methylated on the maternal alleles in BiCHMs. We show, in the BiCHMs from the two sisters, that the abnormally methylated H19 allele is inherited from either the maternal grandmother or the maternal grandfather. These data suggest that the abnormal methylation in BiCHMs is not due to an error in erasing the parental imprinting marks but rather in the re-establishment of the new maternal marks during oogenesis or their postzygotic maintenance. The defective 19q13.4 locus may have led to the development of variable degrees of 'faulty' paternal marks on the maternal chromosomes.
El-Maarri
Osman
O
Institute of Experimental Haematology and Transfusion Medicine, Bonn 53105, Germany.
Seoud
Muhieddine
M
Coullin
Philippe
P
Herbiniaux
Ursula
U
Oldenburg
Johannes
J
Rouleau
Guy
G
Slim
Rima
R
D000293:Adolescent; D000483:Alleles; D001324:Autoantigens / Q000235:genetics; D002864:Chromogranins; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D019175:DNA Methylation; D005260:Female; D019205:GTP-Binding Protein alpha Subunits, Gs; D020022:Genetic Predisposition to Disease; D018392:Genomic Imprinting; D005838:Genotype; D006801:Humans; D006828:Hydatidiform Mole / Q000235:genetics*; D051741:Kruppel-Like Transcription Factors; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics; D010375:Pedigree; D011247:Pregnancy; D011494:Protein Kinases; D011506:Proteins / Q000235:genetics; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics; D013447:Sulfites; D014157:Transcription Factors; D016335:Zinc Fingers; D055517:snRNP Core Proteins
D001324:Autoantigens; D002864:Chromogranins; C094335:H19 long non-coding RNA; D051741:Kruppel-Like Transcription Factors; D009419:Nerve Tissue Proteins; C490820:PEG3 protein, human; D011506:Proteins; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D017411:Ribonucleoproteins, Small Nuclear; C526417:SNRPN protein, human; D013447:Sulfites; D014157:Transcription Factors; D055517:snRNP Core Proteins; D011494:Protein Kinases; C406732:GNAS protein, human; D019205:GTP-Binding Protein alpha Subunits, Gs