TY - JOUR
T1 - Mosaic trisomy 13
T2 - Understanding origin using SNP array
AU - Jinawath, Natini
AU - Zambrano, Regina
AU - Wohler, Elizabeth
AU - Palmquist, Maria K.
AU - Hoover-Fong, Julie
AU - Hamosh, Ada
AU - Batista, Denise A.S.
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/5
Y1 - 2011/5
N2 - Background: Trisomy 13 occurs in 1/10 000e20 000 live births, and mosaicism accounts for 5% of these cases. Phenotype and outcome of mosaic trisomy 13 are variable and poorly understood. Microsatellite analyses of trisomy 13 have indicated the high incidence of maternal meiotic origin and reduced recombination, but no study has focused on mosaic trisomy 13 in live born patients. Methods and results: Single-nucleotide polymorphism (SNP) array, fluorescence in situ hybridisation and bioinformatics analyses were performed in three cases of mosaic trisomy 13. Two cases of complete mosaic trisomy 13 originated from meiosis I non-disjunction followed by trisomic rescue; one had crossovers resulting in segmental uniparental disomy in the disomic line, and one had no crossover. Mosaicism for partial trisomy 13 in the third complex case either arose from meiosis II non-disjunction without crossover or in early mitosis followed by anaphase lags. The extra chromosome 13 was maternal in origin in all three cases. Mosaicism percentage calculated from B allele frequencies ranged from 30 to 50. Conclusions: Genotypes and copy number information provided by SNP array allow determination of parental origin and uniparental disomy status and direct quantification of mosaicism. Such information may lead to a better understanding of mechanisms underlying mosaic aneuploidies and the observed phenotypic variability and better prediction of recurrent risk.
AB - Background: Trisomy 13 occurs in 1/10 000e20 000 live births, and mosaicism accounts for 5% of these cases. Phenotype and outcome of mosaic trisomy 13 are variable and poorly understood. Microsatellite analyses of trisomy 13 have indicated the high incidence of maternal meiotic origin and reduced recombination, but no study has focused on mosaic trisomy 13 in live born patients. Methods and results: Single-nucleotide polymorphism (SNP) array, fluorescence in situ hybridisation and bioinformatics analyses were performed in three cases of mosaic trisomy 13. Two cases of complete mosaic trisomy 13 originated from meiosis I non-disjunction followed by trisomic rescue; one had crossovers resulting in segmental uniparental disomy in the disomic line, and one had no crossover. Mosaicism for partial trisomy 13 in the third complex case either arose from meiosis II non-disjunction without crossover or in early mitosis followed by anaphase lags. The extra chromosome 13 was maternal in origin in all three cases. Mosaicism percentage calculated from B allele frequencies ranged from 30 to 50. Conclusions: Genotypes and copy number information provided by SNP array allow determination of parental origin and uniparental disomy status and direct quantification of mosaicism. Such information may lead to a better understanding of mechanisms underlying mosaic aneuploidies and the observed phenotypic variability and better prediction of recurrent risk.
UR - http://www.scopus.com/inward/record.url?scp=79955533966&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79955533966&partnerID=8YFLogxK
U2 - 10.1136/jmg.2010.083931
DO - 10.1136/jmg.2010.083931
M3 - Article
C2 - 21097773
AN - SCOPUS:79955533966
SN - 0022-2593
VL - 48
SP - 323
EP - 326
JO - Journal of medical genetics
JF - Journal of medical genetics
IS - 5
ER -