Tumor risk in Beckwith-Wiedemann syndrome: A review and meta-analysis

Allogeneic transplantation and the risk for transmission of genetic disease: the heritable cancer disorders

With the development of new approaches to transplantation therapy, such as those building upon the potential found in stem cells, it is vital to pursue a clear understanding of transplantation risks. Allogeneic transplantation presents risk for the transmission of disease of various types, including genetic disease. Predisposition to develop cancer is a feature of numerous genetic disorders, and it may be transmissible by transplantation. Some genetic disorders predisposing to cancer are remarkably common, either worldwide or in specific populations, and they could pose significant risk. Hence, to reduce risk to recipients, there is reason to exclude from donation those potential donors (including embryos) harboring certain germ-line mutations. However, the frequent absence of readily identifiable features might confound the effort to exclude those who harbor mutation. Thus, it is also important to consider the magnitude of risk that they represent. For some disorders, life-threatening cancer is highly likely to develop in those individuals born with germ-line mutation, but whether recipients would face the same risk from transplanted mutation is not always evident. Given the diversity of pathways that lead to cancer, there may be diverse factors that impact the likelihood for cancer to develop in the recipient, with some factors decreasing and others increasing the risk. One factor of special concern is the possibility that manipulation of donor cells, prior to transplantation, might introduce additional genetic or epigenetic abnormality, thereby increasing the risk.

Childhood cancer and birthmarks in the Collaborative Perinatal Project

OBJECTIVE

Three previous retrospective studies noted a positive association between birthmarks and childhood cancer. The objective of this study was to determine whether the incidence of cancer is increased in children with birthmarks relative to those without birthmarks using data from the Collaborative Perinatal Project cohort, a large, prospective study.

METHODS

Our study population comprised 49,503 US children who were born between 1959 and 1968. Birthmarks were documented as definite or suspected during the first year through history or medical examinations and included hemangiomas (port-wine, strawberry, or cavernous), pigmented nevi, lymphangiomas, and café-au-lait spots. The association between birthmarks and childhood cancer was determined using Cox proportional hazards regression.

RESULTS

In the Collaborative Perinatal Project, 2505 individuals had a documented definite or suspected birthmark, including 7 of 47 children who developed cancer. Birthmarks were associated with a significant increase in the risk for cancer. There was a slight attenuation of the risk estimate when cases that were diagnosed in the first year of life were excluded. No specific childhood malignancies were notably affected by birthmarks.

CONCLUSIONS

Although this study was based on a small number of cases, we found birthmarks to be in excess in children who received a diagnosis of cancer using prospective data. These findings provide additional support for the possibility of a shared etiology between birthmarks and childhood cancer that could offer insight into the pathogenesis of pediatric malignancy.

Mesenchymal hamartoma of the liver associated with features of Beckwith-Wiedemann syndrome and high serum alpha-fetoprotein levels

A 5-month-old girl with clinical features of Beckwith-Wiedemann syndrome (BWS), including a repaired omphalocele, an earlobe crease, enlarged adrenal glands, renal size discrepancy, and hyperinsulinemic hyperglycemia, presented with a 1.9-cm liver nodule. Markedly increased serum alpha-fetoprotein (AFP) levels (1,060,000 mg/L), highly suspicious for hepatoblastoma, were detected, and resection of the liver mass was performed. Histologic sections showed features characteristic of a mesenchymal hamartoma of the liver (MHL). No features of embryonal or fetal hepatocellular proliferation or heterologous stromal components were noted. By immunohistochemistry, the hepatocytes expressed AFP, but no nuclear accumulation of beta-catenin was present. Electron microscopy revealed normal, mature hepatocytes. Here we address the diagnostic challenge of the uncommon association of MHL and BWS in the setting of markedly elevated serum AFP levels. In addition, we analyze the unusual pancreatic lesion (focal endocrine adenomatosis) leading to severe hyperinsulinemic hypoglycemia in a patient with possible BWS. We emphasize that MHLs may present with markedly increased serum AFP levels, mimicking hepatoblastomas, and may also be part of the expanding spectrum of findings of BWS.

Tumour surveillance in Beckwith-Wiedemann syndrome and hemihyperplasia: a critical review of the evidence and suggested guidelines for local practice

There is strong evidence for an association between overgrowth disorders such as Beckwith-Wiedemann syndrome and the development of neoplasia. An increased cancer risk has also been observed in individuals with isolated hemihyperplasia. We critically review the evidence for tumour surveillance in Beckwith-Wiedemann syndrome and isolated hemihyperplasia and suggest local practice guidelines.

[Clinical guide to the management of patients with Beckwith-Wiedemann syndrome]

Beckwith-Wiedemann syndrome (BWS) is characterized by congenital overgrowth, macroglossia and omphalocele or umbilical hernia. Children with BWS may also have all or some of the following features: asymmetry (hemihypertrophy) of the limbs, torso or face, hypoglycemia, organomegaly, ear pits or creases, and embryonal tumors. The frequency of BWS is approximately 1:14,000 births. We present a guide for the management of children with BWS aimed at helping pediatricians and general practitioners or specialists in the clinical follow-up of these patients. This guide has been structured according to different age groups and is based on published evidence.

New chromosome 11p15 epigenotypes identified in male monozygotic twins with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is an overgrowth syndrome demonstrating heterogeneous molecular alterations of two imprinted domains on chromosome 11p15. The most common molecular alterations include loss of methylation at the proximal imprinting center, IC2, paternal uniparental disomy (UPD) of chromosome 11p15 and hypermethylation at the distal imprinting center, IC1. An increased incidence of female monozygotic twins discordant for BWS has been reported. The molecular basis for eleven such female twin pairs has been demonstrated to be a loss of methylation at IC2, whereas only one male monozygotic twin pair has been reported with this molecular defect. We report here two new pairs of male monozygotic twins. One pair is discordant for BWS; the affected twin exhibits paternal UPD for chromosome 11p15 whereas the unaffected twin does not. The second male twin pair is concordant for BWS and both twins of the pair demonstrate hypermethylation at IC1. Thus, this report expands the known molecular etiologies for BWS twins. Interestingly, these findings demonstrate a new epigenotype-phenotype correlation in BWS twins. That is, while female monozygotic twins with BWS are likely to show loss of imprinting at IC2, male monozygotic twins with BWS reflect the molecular heterogeneity seen in BWS singletons. These data underscore the need for molecular testing in BWS twins, especially in view of the known differences among 11p15 epigenotypes with respect to tumor risk.

Advances in overgrowth syndromes: clinical classification to molecular delineation in Sotos syndrome and Beckwith-Wiedemann syndrome

PURPOSE OF REVIEW

The clinical importance of overgrowth syndromes in the pediatric patient population has been increasingly recognized during the past decade, but clinical overlap among overgrowth syndromes often makes diagnostic categorization difficult. Advances in the molecular delineation of overgrowth syndromes in recent years have furthered our knowledge of the phenotypic spectrum of this group of conditions. This review focuses on developments in our understanding of the molecular mechanisms and phenotype-genotype correlations in the two most common overgrowth syndromes, Beckwith-Wiedemann syndrome and Sotos syndrome. The implications of these findings with respect to clinical diagnosis, medical management, and genetic counseling are discussed.

RECENT FINDINGS

Recent reports have redefined the cardinal clinical features of Sotos syndrome, and the identification of two distinct types of molecular alterations in patients with this syndrome has enabled assessment of phenotype-genotype correlations. Recent studies in patients with Beckwith-Wiedemann syndrome have further expanded our understanding of the causative molecular mechanisms of this condition and provide evidence for specific genotype-phenotype correlations, most notably with respect to tumor risk.

SUMMARY

Recognition of childhood overgrowth and investigation of diagnostic causes is important in anticipating appropriate medical management and facilitating the provision of genetic counseling. New developments in our understanding of the molecular basis and phenotypic expression of overgrowth syndromes provide additional tools in this often challenging process.

Beckwith-Wiedemann syndrome: historical, clinicopathological, and etiopathogenetic perspectives

Macroglossia, prenatal or postnatal overgrowth, and abdominal wall defects (omphalocele, umbilical hernia, or diastasis recti) permit early recognition of Beckwith-Wiedemann syndrome. Complications include neonatal hypoglycemia and an increased risk for Wilms tumor, adrenal cortical carcinoma, hepatoblastoma, rhabdomyosarcoma, and neuroblastoma, among others. Perinatal mortality can result from complications of prematurity, pronounced macroglossia, and rarely cardiomyopathy. The molecular basis of Beckwith-Wiedemann syndrome is complex, involving deregulation of imprinted genes found in 2 domains within the 11p15 region: telomeric Domain 1 (IGF2 and H19) and centromeric Domain 2 (KCNQ1, KCNQ1OT1, and CDKN1C). Topics discussed in this article are organized as a series of perspectives: general, historical, epidemiologic, clinical, pathologic, genetic/molecular, diagnostic, and differential diagnostic.