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Small supernumerary marker chromosomes: A legacy of trisomy rescue?
Author(s) -
Kurtas Nehir Edibe,
Xumerle Luciano,
Leonardelli Lorena,
Delledonne Massimo,
Brusco Alfredo,
Chrzanowska Krystyna,
Schinzel Albert,
Larizza Daniela,
Guerneri Silvana,
Natacci Federica,
Bonaglia Maria Clara,
Reho Paolo,
Manolakos Emmanouil,
Mattina Teresa,
Soli Fiorenza,
Provenzano Aldesia,
AlRikabi Ahmed H.,
Errichiello Edoardo,
NazaryanPetersen Lusine,
Giglio Sabrina,
Tommerup Niels,
Liehr Thomas,
Zuffardi Orsetta
Publication year - 2019
Publication title -
human mutation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 162
eISSN - 1098-1004
pISSN - 1059-7794
DOI - 10.1002/humu.23683
Subject(s) - biology , nondisjunction , small supernumerary marker chromosome , genetics , uniparental disomy , tetrasomy , haplotype , supernumerary , trisomy , chromosome 21 , chromosome , meiosis , aneuploidy , allele , karyotype , gene , anatomy
We studied by a whole genomic approach and trios genotyping, 12 de novo , nonrecurrent small supernumerary marker chromosomes (sSMC), detected as mosaics during pre‐ or postnatal diagnosis and associated with increased maternal age. Four sSMCs contained pericentromeric portions only, whereas eight had additional non‐contiguous portions of the same chromosome, assembled together in a disordered fashion by repair‐based mechanisms in a chromothriptic event. Maternal hetero/isodisomy was detected with a paternal origin of the sSMC in some cases, whereas in others two maternal alleles in the sSMC region and biparental haplotypes of the homologs were detected. In other cases, the homologs were biparental while the sSMC had the same haplotype of the maternally inherited chromosome. These findings strongly suggest that most sSMCs are the result of a multiple‐step mechanism, initiated by maternal meiotic nondisjunction followed by postzygotic anaphase lagging of the supernumerary chromosome and its subsequent chromothripsis.