Nesidioblastosis and mixed hamartoma of the liver in Beckwith-Wiedemann syndrome: case study including analysis of H19 methylation and insulin-like growth factor 2 genotyping and imprinting.
An infant with persistent hyperinsulinemic hypoglycemia, diffuse nesidioblastosis, and mixed hamartoma of the liver (MHL), in addition to demonstrating clinical, pathologic, and molecular manifestations of Beckwith-Wiedemann syndrome (BWS), is the subject of this report. H19 methylation assay and allelic expression analysis for insulin-like growth factor 2 (IGF2) indicated that the patient was mosaic for paternal isodisomic cells and normal cells in lung tissue, nontumoral liver tissue, tissue from the MHL, and pancreatic tissue. We propose that abundant IGF2 expression during development due to paternal isodisomy resulted in hepatomegaly and islet cell hyperplasia, which led to nesidioblastosis. MHL, by contrast, may have resulted from a decrease in disomic cells, compared with nontumoral liver tissue, which showed an increase in disomic cells. Thus, somatic mosaicism may result in unbalanced tissue growth, which may contribute to the formation of MHL in BWS.
Fukuzawa
R
R
Department of Pathology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
Umezawa
A
A
Morikawa
Y
Y
Kim
K C
KC
Nagai
T
T
Hata
J
J
D022981:Allelic Imbalance; D001506:Beckwith-Wiedemann Syndrome / Q000150:complications / Q000235:genetics / Q000473:pathology*; D019175:DNA Methylation; D017931:DNA Primers / Q000737:chemistry; D017809:Fatal Outcome; D005260:Female; D018392:Genomic Imprinting; D005865:Gestational Age; D006222:Hamartoma / Q000235:genetics / Q000473:pathology*; D006801:Humans; D007231:Infant, Newborn; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000150:complications / Q000235:genetics / Q000473:pathology*; D010182:Pancreatic Diseases / Q000150:complications / Q000151:congenital* / Q000235:genetics; D016133:Polymerase Chain Reaction; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics
D017931:DNA Primers; C094335:H19 long non-coding RNA; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D007335:Insulin-Like Growth Factor II