TY - JOUR
T1 - Quantitative DNA methylation analysis improves epigenotype-phenotype correlations in Beckwith-Wiedemann syndrome
AU - Calvello, Mariarosaria
AU - Tabano, Silvia
AU - Colapietro, Patrizia
AU - Maitz, Silvia
AU - Pansa, Alessandra
AU - Augello, Claudia
AU - Lalatta, Faustina
AU - Gentilin, Barbara
AU - Spreafico, Filippo
AU - Calzari, Luciano
AU - Perotti, Daniela
AU - Larizza, Lidia
AU - Russo, Silvia
AU - Selicorni, Angelo
AU - Sirchia, Silvia M.
AU - Miozzo, Monica
PY - 2013/10
Y1 - 2013/10
N2 - Beckwith-Wiedemann syndrome (BWS) is a rare disorder characterized by overgrowth and predisposition to embryonal tumors. BWS is caused by various epigenetic and/or genetic alterations that dysregulate the imprinted genes on chromosome region 11p15.5. Molecular analysis is required to reinforce the clinical diagnosis of BWS and to identify BWS patients with cancer susceptibility. This is particularly crucial prenatally because most signs of BWS cannot be recognized in utero. We established a reliable molecular assay by pyrosequencing to quantitatively evaluate the methylation profiles of ICR1 and ICR2. We explored epigenotype-phenotype correlations in 19 patients that fulfilled the clinical diagnostic criteria for BWS, 22 patients with suspected BWS, and three fetuses with omphalocele. Abnormal methylation was observed in one prenatal case and 19 postnatal cases, including seven suspected BWS. Seven cases showed ICR1 hypermethylation, five cases showed ICR2 hypomethylation, and eight cases showed abnormal methylation of ICR1 and ICR2 indicating paternal uniparental disomy (UPD). More cases of ICR1 alterations and UPD were found than expected. This is likely due to the sensitivity of this approach, which can detect slight deviations in methylation from normal levels. There was a significant correlation (p <0.001) between the percentage of ICR1 methylation and BWS features: severe hypermethylation (range: 75-86%) was associated with macroglossia, macrosomia, and visceromegaly, whereas mild hypermethylation (range: 55-59%) was associated with umbilical hernia and diastasis recti. Evaluation of ICR1 and ICR2 methylation by pyrosequencing in BWS can improve epigenotype-phenotype correlations, detection of methylation alterations in suspected cases, and identification of UPD.
AB - Beckwith-Wiedemann syndrome (BWS) is a rare disorder characterized by overgrowth and predisposition to embryonal tumors. BWS is caused by various epigenetic and/or genetic alterations that dysregulate the imprinted genes on chromosome region 11p15.5. Molecular analysis is required to reinforce the clinical diagnosis of BWS and to identify BWS patients with cancer susceptibility. This is particularly crucial prenatally because most signs of BWS cannot be recognized in utero. We established a reliable molecular assay by pyrosequencing to quantitatively evaluate the methylation profiles of ICR1 and ICR2. We explored epigenotype-phenotype correlations in 19 patients that fulfilled the clinical diagnostic criteria for BWS, 22 patients with suspected BWS, and three fetuses with omphalocele. Abnormal methylation was observed in one prenatal case and 19 postnatal cases, including seven suspected BWS. Seven cases showed ICR1 hypermethylation, five cases showed ICR2 hypomethylation, and eight cases showed abnormal methylation of ICR1 and ICR2 indicating paternal uniparental disomy (UPD). More cases of ICR1 alterations and UPD were found than expected. This is likely due to the sensitivity of this approach, which can detect slight deviations in methylation from normal levels. There was a significant correlation (p <0.001) between the percentage of ICR1 methylation and BWS features: severe hypermethylation (range: 75-86%) was associated with macroglossia, macrosomia, and visceromegaly, whereas mild hypermethylation (range: 55-59%) was associated with umbilical hernia and diastasis recti. Evaluation of ICR1 and ICR2 methylation by pyrosequencing in BWS can improve epigenotype-phenotype correlations, detection of methylation alterations in suspected cases, and identification of UPD.
KW - BWS
KW - DNA methylation
KW - Genomic imprinting
KW - Pyrosequencing
KW - UPD
UR - http://www.scopus.com/inward/record.url?scp=84884967377&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84884967377&partnerID=8YFLogxK
U2 - 10.4161/epi.25812
DO - 10.4161/epi.25812
M3 - Article
C2 - 23917791
AN - SCOPUS:84884967377
VL - 8
SP - 1053
EP - 1060
JO - Epigenetics
JF - Epigenetics
SN - 1559-2294
IS - 10
ER -