Paternally inherited submicroscopic duplication at 11p15.5 implicates insulin-like growth factor II in overgrowth and Wilms' tumorigenesis

Loss of imprinting at insulin-like growth factor II (IGFII), in association with H19 silencing, has been described previously in a subgroup of Beckwith-Wiedemann syndrome (BWS) patients who have an elevated risk for Wilms' tumor. An equivalent somatic mutation occurs in sporadic Wilms' tumor. We describe a family with overgrowth in three generations and Wilms' tumor in two generations, with paternal inheritance of a cis-duplication at 11p15.5 spanning the BWS IC1 region and including H19, IGFII, INS, and TH. The duplicated region was below the limit of detection by high-resolution karyotyping and fluorescence in situ hybridization, has a predicted minimum size of 400 kb, and was confirmed by genotyping and gene-dosage analysis on a CytoChip comparative genomic hybridization bacterial artificial chromosome array. IGFII is the only known paternally expressed oncogene mapping within the duplicated region and our findings directly implicate IGFII in Wilms' tumorigenesis and add to the mutation spectrum that increases the effective dose of IGFII. Furthermore, this study raises the possibility that sporadic cases of overgrowth and Wilms' tumor, presenting with apparent gain of methylation at IC1, may be explained by submicroscopic paternal duplications. This finding has important implications for determining the transmission risk in these disorders.     

The role of the Intra-aortic balloon pump in supporting children with acute cardiac failure

Acute heart failure occurs in children following the operative correction of a congenital anomaly, as an acute change in a child with a congenital anomaly, or in a structurally normal heart with acute myocarditis. Acute heart failure in children justifies aggressive treatment because of the high potential for complete recovery. The options for providing mechanical support to the failing heart in a child include extracorporeal membrane oxygenation, left ventricular assist devices and the use of the intra-aortic balloon pump (IABP). The principles of intra-aortic balloon pump usage are described, and the literature regarding the indications and outcome of its use in children is reviewed.     

Rapid detection of SMARCB1 sequence variation using high resolution melting

Background  

Rhabdoid tumors are rare cancers of early childhood arising in the kidney, central nervous system and other organs. The majority are caused by somatic inactivating mutations or deletions affecting the tumor suppressor locus SMARCB1 [OMIM 601607]. Germ-line SMARCB1 inactivation has been reported in association with rhabdoid tumor, epitheloid sarcoma and familial schwannomatosis, underscoring the importance of accurate mutation screening to ascertain recurrence and transmission risks. We describe a rapid and sensitive diagnostic screening method, using high resolution melting (HRM), for detecting sequence variations in SMARCB1.     

Coronary artery fistulas in pulmonary atresia and ventricular septal defect

Pulmonary atresia with ventricular septal defect is an anomaly with highly variable anatomy. Rarely, a coronary artery-to-pulmonary artery fistula may contribute to pulmonary blood flow. Since 1996, we have treated 4 patients with coronary-pulmonary fistula associated with pulmonary atresia and ventricular septal defect. Two fistulas originated from the left coronary, one from the right coronary, and one from a right-sided solitary coronary system. All terminated in the main pulmonary artery, which was adequate in all cases. The fistulas were managed by direct internal closure. Total intracardiac repair was then accomplished in all patients at the same sitting. There was one death. In children with favorable anatomy, direct closure of the fistula from the pulmonary artery is adequate and allows single-stage intracardiac repair.