Complete and incomplete forms of Beckwith-Wiedemann syndrome: their oncogenic potential

Occurrence of Hepatoblastomas in Patients with Beckwith-Wiedemann Spectrum (BWSp)

Patients with Beckwith-Wiedemann syndrome (BWS), an epigenetic imprinting disorder involving alterations in genes at the 11p15 chromosomal location, are predisposed to develop hepatoblastomas (HBs), which are rare embryonal liver tumors. Tumors can develop after a BWS diagnosis or, conversely, can be the presenting feature leading to a subsequent diagnosis. While HBs are the cardinal tumors of BWS, not all patients with the BWS spectrum will develop HBs. This observation has led to many hypotheses, including genotype-associated risk, tissue mosaicism, and tumor-specific second hits. To explore these hypotheses, we present the largest cohort of patients with BWS and HBs to date. Our cohort comprised 16 cases, and we broadened our sample size by searching the literature for all cases of BWS with HBs. From these isolated case studies, we amassed another 34 cases, bringing the total number to 50 cases of BWS-HB. We observed that paternal uniparental isodisomy (upd(11)pat) was the most common genotype, representing 38% of cases. The next most common genotype was IC2 LOM, representing 14% of cases. Five patients had clinical BWS without a molecular diagnosis. To investigate the potential mechanism of HBs in BWS, we analyzed normal liver and HB samples from eight cases and isolated tumor samples from another two cases. These samples underwent methylation testing, and 90% of our tumor samples underwent targeted cancer next-generation sequencing (NGS) panels. These matched samples provided novel insights into the oncogenesis of HBs in BWS. We found that 100% of the HBs that underwent NGS panel testing had variants in the CTNNB1 gene. We further identified three distinct groups of BWS-HB patients based on epigenotype. We also demonstrated epigenotype mosaicism, where 11p15 alterations can differ between the blood, HB, and normal liver. In light of this epigenotype mosaicism, tumor risk assessment based on blood profiling may not be accurate. Therefore, universal screening is recommended for all patients with BWS.

Characteristics of Nephroblastoma/Nephroblastomatosis in Children with a Clinically Reported Underlying Malformation or Cancer Predisposition Syndrome

Simple Summary

It is well known that different cancer predisposition syndromes are associated with characteristic WT-features. The following findings from our retrospective analysis of patients with nephroblastoma treated according to the SIOP/GPOH trials between 1989 and 2017 are relevant: (1) The outcome of patients with a cancer predisposition syndrome is not always favorable despite early diagnosis, small tumors and less metastatic disease. This finding is partly depending on complications related to the underlying syndrome. (2) Predisposition syndromes seem to be underdiagnosed as several clinical and pathological features of Wilms tumor being clearly linked to a cancer predisposition syndrome did not lead to genetic counseling before and after WT diagnosis. As a conclusion, in children with a nephroblastoma and specific clinical and pathological features that are in line with a nephroblastoma cancer predisposition syndrome such a syndrome should always be considered and ruled out if unknown at the time of tumor diagnosis.

Abstract

(1) Background: about 10% of Wilms Tumor (WT) patients have a malformation or cancer predisposition syndrome (CPS) with causative germline genetic or epigenetic variants. Knowledge on CPS is essential for genetic counselling. (2) Methods: this retrospective analysis focused on 2927 consecutive patients with WTs registered between 1989 and 2017 in the SIOP/GPOH studies. (3) Results: Genitourinary malformations (GU, N = 66, 2.3%), Beckwith-Wiedemann spectrum (BWS, N = 32, 1.1%), isolated hemihypertrophy (IHH, N = 29, 1.0%), Denys-Drash syndrome (DDS, N = 24, 0.8%) and WAGR syndrome (N = 20, 0.7%) were reported most frequently. Compared to others, these patients were younger at WT diagnosis (median age 24.5 months vs. 39.0 months), had smaller tumors (349.4 mL vs. 487.5 mL), less often metastasis (8.2% vs. 18%), but more often nephroblastomatosis (12.9% vs. 1.9%). WT with IHH was associated with blastemal WT and DDS with stromal subtype. Bilateral WTs were common in WAGR (30%), DDS (29%) and BWS (31%). Chemotherapy induced reduction in tumor volume was poor in DDS (0.4% increase) and favorable in BWS (86.9% reduction). The event-free survival (EFS) of patients with BWS was significantly (p = 0.002) worse than in others. (4) Conclusions: CPS should be considered in WTs with specific clinical features resulting in referral to a geneticist. Their outcome was not always favorable.

Recent advances in Wilms' tumor predisposition

Wilms' tumor (WT), the most common childhood kidney cancer, develops in association with an underlying germline predisposition in up to 15% of cases. Germline alterations affecting the WT1 gene and epigenetic alterations affecting the 11p15 locus are associated with a selective increase in WT risk. Nevertheless, WT also occurs in the context of more pleiotropic cancer predispositions, such as DICER1, Li-Fraumeni and Bloom syndrome, as well as Fanconi anemia. Recent germline genomic investigations have increased our understanding of the host genetic factors that influence WT risk, with sequencing of rare familial cases and large WT cohorts revealing an expanding array of predisposition genes and associated genetic conditions. Here, we describe evidence implicating WT1, the 11p15 locus, and the recently identified genes CTR9, REST and TRIM28 in WT predisposition. We discuss the clinical features, mode of inheritance and biological aspects of tumorigenesis, when known. Despite these described associations, many cases of familial WT remain unexplained. Continued investigations are needed to fully elucidate the landscape of germline genetic alterations in children with WT. Establishing a genetic diagnosis is imperative for WT families so that individuals harboring a predisposing germline variant can undergo surveillance, which should enable the early detection of tumors and use of less intensive treatments, thereby leading to improved overall outcomes.

Chloroquine Triggers Cell Death and Inhibits PARPs in Cell Models of Aggressive Hepatoblastoma

Background: Hepatoblastoma (HB) is the most common pediatric liver malignancy. Despite advances in chemotherapeutic regimens and surgical techniques, the survival of patients with advanced HB remains poor, underscoring the need for new therapeutic approaches. Chloroquine (CQ), a drug used to treat malaria and rheumatologic diseases, has been shown to inhibit the growth and survival of various cancer types. We examined the antineoplastic activity of CQ in cell models of aggressive HB. Methods: Seven human HB cell models, all derived from chemoresistant tumors, were cultured as spheroids in the presence of relevant concentrations of CQ. Morphology, viability, and induction of apoptosis were assessed after 48 and 96 h of CQ treatment. Metabolomic analysis and RT-qPCR based Death Pathway Finder array were used to elucidate the molecular mechanisms underlying the CQ effect in a 2-dimensional cell culture format. Quantitative western blotting was performed to validate findings at the protein level. Results: CQ had a significant dose and time dependent effect on HB cell viability both in spheroids and in 2-dimensional cell cultures. Following CQ treatment HB spheroids exhibited increased caspase 3/7 activity indicating the induction of apoptotic cell death. Metabolomic profiling demonstrated significant decreases in the concentrations of NAD⁺ and aspartate in CQ treated cells. In further investigations, oxidation of NAD⁺ decreased as consequence of CQ treatment and NAD⁺/NADH balance shifted toward NADH. Aspartate supplementation rescued cells from CQ induced cell death. Additionally, downregulated expression of PARP1 and PARP2 was observed. Conclusions: CQ treatment inhibits cell survival in cell models of aggressive HB, presumably by perturbing NAD⁺ levels, impairing aspartate bioavailability, and inhibiting PARP expression. CQ thus holds potential as a new agent in the management of HB.

Characterization of the Beckwith-Wiedemann spectrum: Diagnosis and management

Beckwith-Wiedemann syndrome (BWS) is the most common epigenetic overgrowth and cancer predisposition disorder. Due to both varying molecular defects involving chromosome 11p15 and tissue mosaicism, patients can present with a variety of clinical features, leading to the newly defined Beckwith-Wiedemann spectrum (BWSp). The BWSp can be further divided into three subsets of patients: those presenting with classic features, those presenting with isolated lateralized overgrowth (ILO) and those not fitting into the previous two categories, termed atypical BWSp. Previous reports of patients with BWS have focused on those with the more recognizable, classic features, and limited information is available on those who fit into the atypical and ILO categories. Here, we present the first cohort of patients recruited across the entire BWSp, describe clinical features and molecular diagnostic characteristics, and provide insight into practical diagnosis and management recommendations that we have gained from this cohort.

Expert consensus document: Clinical and molecular diagnosis, screening and management of Beckwith-Wiedemann syndrome: an international consensus statement

Beckwith-Wiedemann syndrome (BWS), a human genomic imprinting disorder, is characterized by phenotypic variability that might include overgrowth, macroglossia, abdominal wall defects, neonatal hypoglycaemia, lateralized overgrowth and predisposition to embryonal tumours. Delineation of the molecular defects within the imprinted 11p15.5 region can predict familial recurrence risks and the risk (and type) of embryonal tumour. Despite recent advances in knowledge, there is marked heterogeneity in clinical diagnostic criteria and care. As detailed in this Consensus Statement, an international consensus group agreed upon 72 recommendations for the clinical and molecular diagnosis and management of BWS, including comprehensive protocols for the molecular investigation, care and treatment of patients from the prenatal period to adulthood. The consensus recommendations apply to patients with Beckwith-Wiedemann spectrum (BWSp), covering classical BWS without a molecular diagnosis and BWS-related phenotypes with an 11p15.5 molecular anomaly. Although the consensus group recommends a tumour surveillance programme targeted by molecular subgroups, surveillance might differ according to the local health-care system (for example, in the United States), and the results of targeted and universal surveillance should be evaluated prospectively. International collaboration, including a prospective audit of the results of implementing these consensus recommendations, is required to expand the evidence base for the design of optimum care pathways.

Beckwith-Weidemann syndrome with IC2 (KvDMR1) hypomethylation defect: a novel mutation

The Beckwith-Wiedemann syndrome (BWS) is a rare genetic syndrome. However, this is one of the most common overgrowth syndromes. This is a genetically and clinically heterogeneous syndrome. Here, we report a case of Beckwith-Weidemann syndrome without macrosomia, visceromegaly and hemihyperplasia but having macroglossia, omphalocele and anterior linear ear lobe creases. The diagnosis was confirmed by gene analysis suggestive of imprinting centre 2 (KvDMR1) hypomethylation defect.

Beckwith-Wiedemann Syndrome: Open bite evolution after tongue reduction

BACKGROUND

Macroglossia causes functional deficits such as airway obstruction, drooling, phonation difficulties, and leads to protrusion of dentoalveolar structures resulting in an anterior open bite and a prognathic mandibular appearance. Macroglossia is present in the majority of patients with Beckwith-Wiedemann syndrome (BWS) and surgical treatment may be indicated.

MATERIAL AND METHODS

A retrospective review was conducted including BWS patients who underwent surgical tongue reduction between 2000 and 2015 at the Hospital Universitario La Paz, Madrid.

RESULTS

Out of 16 patients with BWS, surgery was performed in 11 cases. Tongue protrusion with open bite was the main indication for surgical treatment. Reduction glossectomy was performed using the keyhole technique. We analysed the relationship between age at surgery and evolution of open bite. Complications were minimal and satisfactory outcomes were observed with a decrease in anterior open bite.

CONCLUSIONS

In this study we have observed that surgical treatment in patients with BWS and open bite accompanied by macroglossia seems to provide positive results with a satisfactory outcome in dentoskeletal alterations.

Liver transplantation as definitive treatment of an unresectable mesenchymal hamartoma in a child with Beckwith-Wiedemann Syndrome

Mesenchymal liver hamartomas are benign tumors that can cause life-threatening abdominal distension and carry a risk for malignant transformation. In this case report, we describe a 13-month-old male with Beckwith–Wiedemann Syndrome (BWS) who presented with multiple mesenchymal liver hamartomas causing severe intra-abdominal mass effect. Imaging revealed six large multi-locular cystic lesions, ranging from 3.8 to 8.9 cm in diameter. The large size and spread of the tumors necessitated liver transplantation for complete removal. The patient successfully underwent cadaveric piggyback liver transplantation at 25 months of age. He was alive at 16-month follow-up without evidence of tumor recurrence or graft rejection. Histological examination of the hepatic masses revealed mucinous epithelial lining and abundant hepatocytes in varying stages of differentiation, supporting the diagnosis of mesenchymal hamartoma. To the best of our knowledge, this is the first reported case of liver transplantation in a patient with BWS as definitive treatment for unresectable mesenchymal liver hamartoma.

A case of hepatoblastoma misdiagnosed as combined hepatocellular carcinoma and cholangiocarcinoma in an adult

Hepatoblastoma usually occurs in children under the age of 2 years, with very few cases reported in adults. We experienced a case of adult hepatoblastoma in a 36-year-old female with chronic hepatitis B. She had experienced sudden onset abdominal pain. Her serum alpha-fetoprotein level was markedly elevated, and abdominal CT showed a 9-cm mass with internal hemorrhage in the right hepatic lobe with hemoperitoneum, so an emergency hepatic central bisectionectomy was performed. The initial histologic examination revealed that the mass mimicked combined hepatocellular carcinoma and cholangiocarcinoma with spindle-cell metaplasia of the cholangiocarcinoma element. Follow-up abdominal CT performed 3 months later showed a 5.5-cm metastatic mass in the left subphrenic area. Laparoscopic splenectomy with mass excision was performed, and hepatoblastoma was confirmed histologically. A histologic re-examination of previously obtained surgical specimens also confirmed the presence of hepatoblastoma. Metastatic hepatoblastoma was found at multiple sites of the abdomen during follow-up, and so chemotherapy with cisplatin, 5-fluorouracil (5-FU), and vincristine was applied, followed by carboplatin and doxorubicin. Despite surgery and postoperative chemotherapy, she died 12 months after symptom onset.

Long-term orthodontic and surgical treatment and stability of a patient with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is a congenital growth disorder. Children born with BWS develop enlarged organs, including the tongue, a large body, and other signs. A woman with BWS was treated and followed for 30 years. Treatment consisted of tongue reduction, orthopedic and orthodontic treatment, orthognathic surgery, and retention. The patient was first treated when she was 5 years old. Her original orthodontic problems included macroglossia, anterior open bite, anterior crossbite, and a skeletal Class III jaw relationship caused by significant mandibular protrusion. The jaw-base relationships did not improve in the early preadolescent period after phase 1 of orthodontic treatment with a vertical chincap. With the growth spurt accompanying puberty, she developed a severe skeletal Class III jaw relationship and a constricted maxillary arch. Surgically assisted rapid maxillary expansion was performed at 23 years of age to correct the severe discrepancy between the maxillary and mandibular dental arch widths. Then, at 26 years, a LeFort I osteotomy, a horseshoe osteotomy, a bilateral sagittal split ramus osteotomy, and genioplasty were performed after presurgical orthodontic treatment with extraction of the mandibular first molars. Both the facial profile and the occlusion were stable after 6 years of retention. This case report discusses the result of long-term observation of a patient with BWS who underwent tongue reduction, early orthodontic treatment, and surgical-orthodontic treatment.

Malformations, genetic abnormalities, and Wilms tumor

BACKGROUND

Wilms Tumor (WT) can occur in association with tumor predisposition syndromes and/or with clinical malformations. These associations have not been fully characterized at a clinical and molecular genetic level. This study aims to describe clinical malformations, genetic abnormalities, and tumor predisposition syndromes in patients with WT and to propose guidelines regarding indications for clinical and molecular genetic explorations.

PROCEDURE

This retrospective study analyzed clinical abnormalities and predisposition syndromes among 295 patients treated for WT between 1986 and 2009 in a single pediatric oncological center.

RESULTS

Clinically identified malformations and predisposition syndromes were observed in 52/295 patients (17.6%). Genetically proven tumor predisposition syndromes (n = 14) frequently observed were syndromes associated with alterations of the chromosome WT1 region such as WAGR (n = 6) and Denys-Drash syndromes (n = 3), syndromes associated with alterations of the WT2 region (Beckwith-Wiedeman syndrome, n = 3), and Fanconi anemia (n = 2). Hemihypertrophy and genito-urinary malformations (n = 12 and n = 16, respectively) were the most frequently identified malformations. Other different syndromes or malformations (n = 10) were less frequent. Median age of WT diagnosis was significantly earlier for children with malformations than those without (27 months vs. 37 months, P = 0.0009). There was no significant difference in terms of 5-year EFS and OS between WT patients without or with malformations.

CONCLUSIONS

The frequency of malformations observed in patients with WT underline the need of genetic counseling and molecular genetic explorations for a better follow-up of these patients, with a frequently good outcome. A decisional tree, based on clinical observations of patients with WT, is proposed to guide clinicians for further molecular genetic explorations.

Giant breast tumors in a patient with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is an overgrowth disorder with increased risk of embryonal tumors, such as Wilms tumor, hepatoblastoma, neuroblastoma, and rhabdomyosarcoma. We report on a patient with BWS that developed a giant fibroadenoma of the breast that was surgically removed. The tumor relapsed 8 months after the surgery and the patient underwent partial mastectomy. Although the patient presented several clinical features of BWS, a molecular diagnosis was not achieved despite extensive molecular investigations on both blood and tumor tissue. A SNP array revealed a de novo 7p22.1 loss in both blood and breast tumor involving the mismatch repair gene PMS2 gene that may be potentially associated with the breast tumor. In conclusion, it remains unclear whether BWS patients have an increased risk of breast lesions or a yet unknown molecular defect is responsible for the rare occurrence of this tumor in BWS.

Oxford and the Savannah: can the hippo provide an explanation for Peto's paradox?

Peto's paradox is the counterintuitive finding that increasing body mass and thereby cell number does not correlate with an increase in cancer incidence across different species. The Hippo signaling pathway is an evolutionarily conserved system that determines organ size by regulating apoptosis and cell proliferation. It also affects cell growth by microRNA-29 (miR-29)-mediated cross-talk to the mTOR signaling pathway. Whether these pathways that decide organ size could explain this paradox merits consideration. Inactivation of most genes of the Hippo pathway in Drosophila melanogaster genetic screens causes excessive tissue-specific growth of developing tissues. Altered Hippo pathway activity is frequently found in diverse tumor types, but mutations of component pathway genes are rare. Most Hippo pathway components are encoded by tumor suppressor genes (TSG), but an exception is the downstream effector gene called YAP. Activity of the Hippo pathway causes deactivating phosphorylation of YES-associated protein (YAP) with nuclear exclusion. YAP can also be phosphorylated at a second site, S127, by AKT. YAP induces the expression of genes responsible for proliferation and suppression of apoptosis. Resolving Peto's paradox may serendipitously provide new insights into the biology and treatment of cancer. This article considers Hippo signaling and Peto's paradox in the context of TSG-oncogene computed models. Interspecies differences in dietary composition, metabolic rates, and anabolic processes are also discussed in the context of Hippo-mTOR signaling. The metabolically important LKB1-AMPK (liver kinase B1-AMP activated protein kinase) signaling axis that suppresses the mTOR pathway is also considered.

Diagnosis and staging of hepatoblastoma: imaging aspects

Imaging plays a pivotal role in the diagnosis and management of children with hepatoblastoma. However, the continuing evolution of imaging technologies and rarity of hepatoblastoma make validation of imaging approaches challenging. In Europe and other parts of the world staging of hepatoblastoma is based on imaging features while in North America it is based on surgical resectability. In this review we discuss the clinical and imaging features that aid in diagnosing and monitoring children with hepatoblastoma. The potential roles of new imaging techniques are presented, and differences between staging systems are addressed.

Hepatoblastoma in a mosaic trisomy 18 patient

We report a case of hepatoblastoma in a 10-year-old girl with mosaic-type trisomy 18. A comprehensive literature review reveals only 2 cases involving mosaic trisomy 18 patients. Our patient underwent an abbreviated chemotherapy course before complete surgical resection. Her hepatoblastoma did not contain cells with trisomy 18. The conservative management approach resulted in a successful outcome; she remains disease free >2 years after surgery. Along with presenting a literature review, this report demonstrates a favorable outcome in a mosaic trisomy 18 child with hepatoblastoma where tumor cells lacked a trisomy 18 karyotype.

Adrenocortical stem and progenitor cells: implications for adrenocortical carcinoma

The continuous centripetal repopulation of the adrenal cortex is consistent with a population of cells endowed with the stem/progenitor cell properties of self-renewal and pluripotency. The adrenocortical capsule and underlying undifferentiated cortical cells are emerging as critical components of the stem/progenitor cell niche. Recent genetic analysis has identified various signaling pathways including Sonic Hedgehog (Shh) and Wnt as crucial mediators of adrenocortical lineage and organ homeostasis. Shh expression is restricted to the peripheral cortical cells that express a paucity of steroidogenic genes but give rise to the underlying differentiated cells of the cortex. Wnt/β-catenin signaling maintains the undifferentiated state and adrenal fate of adrenocortical stem/progenitor cells, in part through induction of its target genes Dax1 and inhibin-α, respectively. The pathogenesis of ACC, a rare yet highly aggressive cancer with an extremely poor prognosis, is slowly emerging from studies of the stem/progenitor cells of the adrenal cortex coupled with the genetics of familial syndromes in which ACC occurs. The frequent observation of constitutive activation of Wnt signaling due to loss-of-function mutations in the tumor suppressor gene APC or gain-of-function mutation in β-catenin in both adenomas and carcinomas, suggests perhaps that the Wnt pathway serves an early or initiating insult in the oncogenic process. Loss of p53 might be predicted to cooperate with additional genetic insults such as IGF2 as both are the most common genetic abnormalities in malignant versus benign adrenocortical neoplasms. It is unclear whether other factors such as Pod1 and Pref1, which are implicated in stem/progenitor cell biology in the adrenal and/or other organs, are also implicated in the etiology of adrenocortical carcinoma. The rarity and heterogeneous presentation of ACC makes it difficult to identify the cellular origin and the molecular progression to cancer. A more complete understanding of adrenocortical stem/progenitor cell biology will invariably aid in characterization of the molecular details of ACC tumorigenesis and may offer new options for therapeutic intervention.

Surgical treatment of macroglossia in patients with Beckwith-Wiedemann syndrome: a 20-year experience and review of the literature

Macroglossia is observed in the majority of paediatric patients diagnosed with Beckwith-Wiedemann syndrome and surgical treatment may be indicated. A 20-year retrospective study was performed to evaluate all patients with Beckwith-Wiedemann syndrome who underwent tongue reduction surgery at the authors' institution. A literature review was performed. Surgical treatment was indicated and carried out in 23 patients with a yearly average varying from 0 to 3 subjects. The mean follow-up time was 7 years. Primary indications for surgical treatment of macroglossia included significant tongue protrusion in 30% (n=7), and a combination of clinical problems in 70% (n=16). In all cases, the procedure was performed by the same surgeon using an anterior, V-shaped, wedge resection technique. Two patients had direct postoperative complications. No recurrence of macroglossia was observed in this study. Reported clinical outcome during follow-up demonstrated a satisfactory resting tongue position in all patients. Review of the literature demonstrated variability in surgical indications and techniques, and postoperative outcome. The results of this study indicate that the anterior wedge resection is a simple, effective and safe technique in the surgical treatment of paediatric patients, diagnosed with Beckwith-Wiedemann syndrome, suffering from macroglossia.

A review of the urologic manifestations of Beckwith-Wiedemann syndrome

OBJECTIVE

Beckwith-Wiedemann syndrome (BWS) is a constellation of congenital anomalies that classically presents with macroglossia, abdominal wall defects and gigantism. Although renal and adrenal pathology are the most commonly associated urologic findings of BWS, we report a case of a girl with BWS and symptomatic clitoromegaly, recurrent urinary tract infections and vesicoureteral reflux, followed by a review of the literature regarding urologic manifestations of BWS.

MATERIALS AND METHODS

A comprehensive review of the literature for renal and non-renal urologic manifestations of BWS was conducted using a computer-based (PubMed) search. The reported renal and non-renal urologic findings are summarized.

RESULTS

In addition to well-described renal manifestations, a variety of non-renal urologic findings have been reported in patients with BWS.

CONCLUSIONS

Healthcare providers should carefully evaluate both patients and their family members for urologic manifestations of BWS. Early diagnosis and thorough evaluation allows for potential improved management and prognosis of BWS urologic sequelae, including tumors, cryptorchidism and urinary tract abnormalities.

Adrenal masses associated with Beckwith Wiedemann syndrome in the newborn

Adrenal cystic lesions are rare and may be associated with both complete and incomplete Beckwith syndrome (BWS). Because the adrenal gland often houses malignant lesions, differentiation between benign and malignant lesions of the gland, although usually difficult, is very necessary from the point of view of management. Here we present our experience in a case of incomplete BWS with adrenal cystic lesion and review of the literature.

Addition of H19 'loss of methylation testing' for Beckwith-Wiedemann syndrome (BWS) increases the diagnostic yield

Beckwith-Wiedemann syndrome (BWS) is a clinical diagnosis; however, molecular confirmation via abnormal methylation of DMR2(LIT1) and/or DMR1(H19) has clinical utility due to epigenotype-tumor association. Despite the strong link between H19 hypermethylation and tumor risk, several diagnostic laboratories only test for hypomethylation of LIT1. We assessed the added diagnostic value of combined LIT1 and H19 testing in a large series of referred samples from 1298 patients, including 53 well-characterized patients from the St. Louis Children's Hospital BWS-Registry (validation samples) and 1245 consecutive nationwide referrals (practice samples). Methylation-sensitive enzymatic digestion with Southern hybridization assessed loss of normal imprinting. In the validation group, abnormal LIT1 hypomethylation was detected in 60% (32/52) of patients but LIT1/H19-combined testing was abnormal in 68% (36/53); sensitivity in the practice setting demonstrated 27% (342/1245) abnormal LIT1 and 32% (404/1245) abnormal LIT1/H19-combined. In addition, H19 methylation was abnormal in 7% of LIT1-normal patients. We observed absence of uniparental disomy (UPD) in 27% of combined LIT1/H19-abnormal samples, diagnostic of multilocus methylation abnormalities; in contrast to studies implicating that combined LIT1/H19 abnormalities are diagnostic of UPD. The overall low detection rate, even in validated patient samples and despite characterization of both loci and UPD status, emphasizes the importance of clinical diagnosis in BWS.

Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is a model disorder for the study of imprinting, growth dysregulation, and tumorigenesis. Unique observations in this disorder point to an important embryonic developmental window relevant to the observations of increased monozygotic twinning and an increased rate of epigenetic errors after subfertility/assisted reproduction.

Two Infants with Beckwith-Wiedemann Syndrome

Beckwith-Wiedemann syndrome (BWS; OMIM 130650) is an overgrowth disorder characterized by macrosomia, macroglossia, organomegaly and developmental abnormalities (in particular abdominal wall defects with exomphalos) and a multi genetic disorder caused by dysregulation of genes expressed in the imprinted 11p15 chromosomal region. We report two unrelated male Moroccan firstborn infants who were hospitalized for macroglossia with breathing difficulties associated with other malformations indicative of BWS.

Lessons from BWS twins: complex maternal and paternal hypomethylation and a common source of haematopoietic stem cells

The Beckwith-Wiedemann syndrome (BWS) is a growth disorder for which an increased frequency of monozygotic (MZ) twinning has been reported. With few exceptions, these twins are discordant for BWS and for females. Here, we describe the molecular and phenotypic analysis of 12 BWS twins and a triplet; seven twins are MZ, monochorionic and diamniotic, three twins are MZ, dichorionic and diamniotic and three twins are dizygotic. Twelve twins are female. In the majority of the twin pairs (11 of 13), the defect on chromosome 11p15 was hypomethylation of the paternal allele of DMR2. In 5 of 10 twins, there was additional hypomethylation of imprinted loci; in most cases, the loci affected were maternally methylated, but in two cases, hypomethylation of the paternally methylated DLK1 and H19 DMRs was detected, a novel finding in BWS. In buccal swabs of the MZ twins who share a placenta, the defect was present only in the affected twin; comparable hypomethylation in lymphocytes was detected in both the twins. The level of hypomethylation reached levels below 25%. The exchange of blood cells through vascular connections cannot fully explain the degree of hypomethylation found in the blood cell of the non-affected twin. We propose an additional mechanism through which sharing of aberrant methylation patterns in discordant twins, limited to blood cells, might occur. In a BWS-discordant MZ triplet, an intermediate level of demethylation was found in one of the non-affected sibs; this child showed mild signs of BWS. This finding supports the theory that a methylation error proceeds and possibly triggers the twinning process.

Nasal encephalocele in a child with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is a rare congenital syndrome characterized by gigantism, macroglossia, exophthalmos, postpartum hypoglycemia, and multiple midline defects such as omphalocele. The authors describe, to the best of their knowledge, the first case of a child in whom BWS was diagnosed and who was subsequently treated for a nasal encephalocele. Because the authors believe that this feature might not be an incidental finding in patients with BWS, intranasal masses in these patients should be carefully differentiated, as complications might be severe.

Anesthetic management of two cases of Beckwith-Wiedemann syndrome

Two cases of children with Beckwith-Wiedemann syndrome are presented. This syndrome consists of various abnormalities, including macroglossia, visceromegaly, omphalocele, and gigantism. These abnormalities frequently require operative correction during the neonatal period. We anesthesiologists should make plans for difficult airway managements in patients with this syndrome. Our two patients also showed larger sized tracheas than those estimated by their age and height. A cuffed tube, though still controversial, has recently been used in children. We recommend using a cuffed tube in patients with this syndrome, because the appropriate tracheal size may not be predictable, tracheal intubation might be difficult, and risks incurred during changing of a tracheal tube should be avoided.

Epidemiology of genetically determined cancer

Dominantly heritable susceptibility is known for virtually every cancer. Susceptibility is typically restricted to one or a few tumours. For some tumours there appear to be at least two different predisposing conditions. Some mutant gene carriers survive to old age without developing the expected tumour(s). Some cases are new germline mutations. None of the conditions is very common, because of natural selection against gene carriers. Two questions arise: What is inherited? What is the relationship between the hereditary and non-hereditary forms of the same tumour? Retinoblastoma is a prototypic tumour. Penetrance in humans is nearly complete by the age of five years in the heritable form, which usually affects both eyes. Rare cases in which there is a constitutional deletion of chromosomal band 13q14 permitted localization of the responsible gene. Tumour formation is clearly a rare event at the cellular level, suggesting the necessity of a second, somatic, event. The difference in ages at diagnosis between unilateral and bilateral cases also suggests that two somatic events occur in non-hereditary cases. One explanation is that the gene is recessive and the second event involves loss of the remaining normal allele by mutation, non-disjunction, deletion or somatic recombination. The normal allele may be regarded as anti-oncogenic.

Long-term outcomes of surgical tongue reduction in Beckwith-Wiedemann syndrome

BACKGROUND

Surgical tongue reduction is often performed in Beckwith-Wiedemann syndrome when macroglossia results in abnormal tongue function or cosmesis; however, no published studies have examined the long-term outcomes of this procedure.

METHODS

Patients older than 18 years with Beckwith-Wiedemann syndrome who had previously undergone surgical tongue reduction at the Royal Children's Hospital in Melbourne underwent assessment of speech and tongue function, mobility, sensation, and cosmesis. These assessments were performed by questionnaire on 11 subjects and by formal medical and speech pathology review in four of these 11 subjects.

RESULTS

Eleven patients aged 19 to 31 years completed responses by means of questionnaire. The most common self-reported abnormalities were continued disproportionate tongue bulk (91 percent), abnormal tongue appearance (82 percent), specific speech sound errors (73 percent), and a short tongue tip (55 percent). Formal assessments investigated speech, swallowing, taste, and tongue mobility in four quite different subjects. One of these four subjects had no detectable deficits in tongue function. All 11 patients were of normal intelligence and did not report significant difficulties in their day-to-day life that were attributable to their macroglossia or tongue reduction surgery.

CONCLUSIONS

Pediatric patients with symptomatic macroglossia requiring surgical tongue reduction may not achieve complete normality in tongue function and appearance in adulthood. It is important that surgical tongue reduction addresses the global nature of the macroglossia and aims to retain a tapered tongue tip with length sufficient to permit normal tongue movements.

Syndromes and constitutional chromosomal abnormalities associated with Wilms tumour

Wilms tumour has been reported in association with over 50 different clinical conditions and several abnormal constitutional karyotypes. Conclusive evidence of an increased risk of Wilms tumour exists for only a minority of these conditions, including WT1 associated syndromes, familial Wilms tumour, and certain overgrowth conditions such as Beckwith-Wiedemann syndrome. In many reported conditions the rare co-occurrence of Wilms tumour is probably due to chance. However, for several conditions the available evidence cannot either confirm or exclude an increased risk, usually because of the rarity of the syndrome. In addition, emerging evidence suggests that an increased risk of Wilms tumour occurs only in a subset of individuals for some syndromes. The complex clinical and molecular heterogeneity of disorders associated with Wilms tumour, together with the apparent absence of functional links between most of the known predisposition genes, suggests that abrogation of a variety of pathways can promote Wilms tumorigenesis.

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.

Bilateral hemorrhagic adrenal cysts in an incomplete form of Beckwith-Wiedemann syndrome: MRI and prenatal US findings

Benign hemorrhagic adrenal cysts are a cause of subdiaphragmatic mass in the fetus and neonate with Beckwith-Wiedemann syndrome. Characteristic imaging features on ultrasonography, color Doppler, and magnetic resonance imaging help differentiate adrenal hemorrhage from neonatal neuroblastoma and help avoid unnecessary surgery in these patients. Bilateral adrenal hemorrhage is self-limiting, and spontaneous resolution is the usual outcome. This report presents this rare condition with prenatal ultrasonographic and magnetic resonance imaging findings and reviews the differential diagnosis of neonatal adrenal masses.

Malignant adrenal tumors

Adrenal tumors, apart from neuroblastoma, are relatively rare in infancy and childhood. Most adrenal lesions are benign, and both benign and malignant tumors may be hormonally active thus, making accurate preoperative diagnosis difficult. The two main malignant tumors are adrenocortical carcinoma and pheochromocytoma. In both tumors, it may be difficult to determine benign from malignant and the biologic behavior and degree of invasion may portend a more malignant course. Surgical excision is the primary therapy for both tumors, including excision of metastatic and recurrent tumor. An open procedure should be considered for invasive adrenocortical carcinoma and in pheochromocytomas in which preoperative imaging demonstrates metastatic nodal disease. A laparoscopic approach is preferred for lesions in which preoperative imaging demonstrates a localized lesion. Chemotherapy, although without proven efficacy, is utilized in some children with metastatic or unresectable disease.

Renal cell carcinoma as a second malignant neoplasm in a patient with non-syndromic hemihypertrophy and previous Wilms tumor

Survivors of childhood Wilms tumors are at an increased risk of second malignant neoplasms. Recently, it has been postulated that renal cell carcinoma is among the malignancies for which this population is at risk. We present the unique case of an adult Wilms tumor survivor with non-syndromic hemihypertrophy (NSHH) who developed renal cell carcinoma. This case highlights the need for close follow-up in two populations: adults who have survived Wilms tumor and those with NSHH.

Follow-up and risk of tumors in overgrowth syndromes

A striking feature of the overgrowth syndromes (OGS) is the risk of cancer. In some OGS (Beckwith-Wiedemann, Perlman, Simpson-Golabi-Behmel syndromes and hemihypertrophy) tumors appeared mostly in the abdomen (more than 94% of tumors), are usually diagnosed before 10 years, and most of them are embryonal. Conversely, in other OGS, such as Sotos syndrome, the most frequent type is lympho-hematological tumors, about two-thirds are extra-abdominal and some of these tumors may appear after the second decade of life. Based on a previous literature review, a specific schedule protocol for tumor screening was suggested for many OGS. In this article we briefly review some aspects of the current knowledge of OGS and tumors, emphasizing the follow-up of these disorders.

Beckwith-Wiedemann syndrome and bilateral adrenal pheochromocytoma: sonography and MRI findings

Beckwith-Wiedemann syndrome is characterized by a group of clinical abnormalities, the most frequent of which are omphalocele, macroglossia, gigantism, neonatal hypoglycemia and umbilical hernia. The association of this syndrome with malignant tumors is well documented. We report a child with this syndrome associated with bilateral adrenal pheochromocytoma.

Prenatal diagnosis of fetal bilateral adrenal carcinoma

Fetal malignancies that are capable of metastasizing to other fetal organs and the placenta are exceedingly rare. Fetal tumors are suspected on ultrasonography in the presence of structures of abnormal shape or size that are occasionally associated with polyhydramnios and hydrops. Most of the large abdominal masses detected antenatally are renal in origin, although adrenal tumors should also be kept in mind in their differential diagnosis. We report a case of a large-for-gestational-age fetus with abdominal distention secondary to bilateral adrenal carcinoma, polyhydramnios and placental enlargement. Postmortem histological findings included nesidioblastosis, (i.e. hyperplasia of the cells of the islets of Langerhans) and adrenocortical cytomegaly, suggestive of a form of Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is a clinically heterogeneous overgrowth syndrome associated with an increased risk for embryonal tumor development. BWS provides an ideal model system to study epigenetic mechanisms. This condition is caused by a variety of genetic or epigenetic alterations within two domains of imprinted growth regulatory genes on human chromosome 11p15. Molecular studies of BWS have provided important data with respect to epigenotype/genotype-phenotype correlations; for example, alterations of Domain 1 are associated with the highest risk for tumor development, specifically Wilms' tumor. Further, the elucidation of the molecular basis for monozygotic twinning in BWS defined a critical period for imprint maintenance during pre-implantation embryonic development. In the future, such molecular studies in BWS will permit enhanced medical management and targeted genetic counseling.

Risk of tumorigenesis in overgrowth syndromes: a comprehensive review

Overgrowth syndromes (OGS) comprise a heterogeneous group of disorders in which the main characteristic is that either weight, height, or head circumference is 2-3 standard deviations (SD) above the mean for sex and age. A striking feature of OGS is the risk of neoplasms. Here, the relative frequency of specific tumors in each OGS, topographic location, and age of appearance is determined by reviewing published cases. In some OGS (Perlman, Beckwith-Wiedemann, and Simpson-Golabi-Behmel syndromes and hemihyperplasia) more than 94% of tumors appeared in the abdomen usually before 10 years of age, mainly embryonal in type. In Perlman syndrome, only Wilms tumor has been recorded, whereas in Sotos syndrome, lympho-hematologic tumors are most frequent. Based on literature review, a specific schedule protocol for tumor screening is suggested for each OGS. A schedule with different intervals and specific tests is proposed for a more rational cost/benefit program for these disorders.

Focal nodular hyperplasia in a child with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann Syndrome (BWS) is associated with somatic overgrowth and a high risk for embryonal tumors, including hepatoblastoma, a highly malignant liver tumor of childhood. Focal nodular hyperplasia (FNH), on the other hand, is a benign tumor of the liver that is uncommon in childhood. Herein we describe a case of FNH in a child with BWS, the first such report in the literature.

Pancreatoblastoma associated with incomplete Beckwith-Wiedemann syndrome: case report and review of the literature

A case of pancreatoblastoma (PB) in a 2 month-old male infant with incomplete Beckwith-Wiedemann syndrome is presented. Clinical examination disclosed left hemihypertrophy, macroglossia, bilateral exophthalmos, and enlargement of the left testis. Imaging with ultrasound and computed tomography scan showed a well-defined, heterogeneous, and grossly cystic mass arising from the head of the pancreas. Serum alpha-fetoprotein (AFP) level was elevated. The tumor was completely resected, and the histological analysis showed PB. The patient's recovery was uneventful, and AFP returned to normal values after surgery. The child has been disease-free for 5 years, and his serum AFP remained within normal values. Six other examples of this association, PB, and Beckwith-Wiedemann syndrome are recorded in the literature. The risk of developing tumor in this syndrome (complete and incomplete form) increases when hemihypertrophy is present, and the need for routine screening examination is warranted. Beckwith-Wiedemann syndrome was suggested to be a favorable biological marker for survival in children who have intraabdominal tumors.

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.

Prenatal diagnosis of Beckwith-Wiedemann syndrome

OBJECTIVES

The diagnosis of Beckwith-Wiedemann syndrome (BWS) typically is made after birth. To our knowledge, no established guidelines exist for the prenatal diagnosis of this condition. We present two new cases of prenatally diagnosed BWS and propose a diagnostic schema.

METHODS

Published reports obtained from Medline searches were reviewed and combined with our cases.

RESULTS

Our proposed schema of two major criteria (abdominal wall defect, macroglossia, macrosomia) or one major plus two minor criteria (nephromegaly/dysgenesis, adrenal cytomegaly, aneuploidy/abnormal loci, polyhydramnios) fits all published reports of prenatally diagnosed BWS.

CONCLUSION

The prenatal diagnosis of BWS can be reliably made by applying our proposed guidelines. This schema allows for uniform fetal diagnosis of the syndrome and helps prepare for prenatal counseling and peri- and post-natal management strategies.

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

Beckwith-Wiedemann syndrome (BWS) is an overgrowth syndrome associated with macroglossia, abdominal wall defects, ear anomalies, and an increased risk for embryonic tumors. Reported tumor risk estimates vary between 4% and 21%. It has been hypothesized that tumor predisposition in BWS is related to the imprinting status of the H19 and LIT1 genes on chromosome 11p15. A loss of imprinting (LOI) of H19 implies a higher tumor risk. However, a systematic analysis of available data is lacking. Therefore, we performed a review and meta-analysis of reported associations between the imprinting status of the LIT1 and H19 genes and the risk for tumor development in BWS. Five publications suitable for meta-analysis were identified by electronic database searches. Sufficient data were available for 402 out of 520 patients. Patients were divided into four groups based on the imprinting status of H19 and LIT1: group I with LOI of LIT1 (45%); group II with LOI of H19 (9%); group III with LOI of LIT1 and LOI of H19 (21%); and group IV with normal imprinting patterns (26%). Differences in tumor risk between groups were studied with random effects meta-analysis. Tumors occurred in 55 patients. The odds of tumor development was significantly lower in group I when compared to group II (OR=0.06; 95% CI: 0.02-0.21) and group III (OR=0.12; 95% CI: 0.04-0.37). Tumor risk did not differ significantly between groups II and III (OR=1.40; 95% CI: 0.56-3.50). Compared to group IV, tumor risk was significantly lower in group I (OR=0.33; 95% CI: 0.12-0.87) and higher in groups II (OR=4.0; 95% CI: 1.5-10.4) and III (OR=2.6; 95% CI: 1.2-5.7). Tumor incidence rate for group IV was 10.6% (95% CI: 3.6-17.7). Calculated absolute risks were 3% for group I, 43% for group II, and 28% for group III, respectively. No Wilms tumor was seen in group I. In total, other tumors were seen with comparable frequencies in groups I-III. The results show a strong association between a LOI of H19 and especially Wilms tumor development in BWS.

Epigenotyping as a tool for the prediction of tumor risk and tumor type in patients with Beckwith-Wiedemann syndrome (BWS)

OBJECTIVES

Patients with Beckwith-Wiedemann syndrome (BWS) have a risk of 7.5% to 10% of developing childhood tumors, 60% of which are Wilms' tumors. Aberrant methylation of two distinct clusters of imprinted genes on chromosome 11p15 is detected in approximately 70% of BWS cases. Our aim was to determine associations between the imprinting status of both imprinting clusters (BWSIC1/2) and the tumor incidence and type.

STUDY DESIGN

Methylation patterns of H19 and KCNQ1OT1 were collected in 114 patients with BWS with a clinical diagnosis. The patients were followed until 5 years of age, and tumor incidence and type were registered.

RESULTS

A lower risk of developing childhood tumors was found among patients with a methylation defect limited to BWSIC2 compared with other patients with BWS. No Wilms' tumors were found in this group, whereas in patients with a methylation defect limited to BWSIC1 Wilms' tumor was the most common tumor.

CONCLUSIONS

In addition to clinical factors indicative for a high tumor risk (hemihypertrophy, nephromegaly), methylation patterns discriminate between patients with BWS with a high and low tumor risk. It also is possible to predict whether they are at risk of developing a Wilms' tumor. Epigenotyping of patients is important to select the type of screening protocol to be proposed to these patients.

Epidemiology and genetics of childhood cancer

Childhood cancer is rare everywhere in the world, with age-standardized annual incidence usually between 70 and 160 per million at age 0-14 years. Greater variation is seen between populations for some specific tumour types. Some of the largest variations are geographical and are attributable to environmental factors, whereas variation mainly on ethnic lines seems likely to be a marker of genetic predisposition. A wide range of familial and genetic syndromes is associated with an increased risk of childhood cancer. Virtually all the excess risk of cancer among first-degree relatives of children with cancer can be accounted for by known hereditary syndromes. Studies of weak predisposition and gene-environment interaction have so far shown limited consistency. There are very few established environmental or exogenous risk factors and most of these are infective agents. Many putative risk factors can hardly ever be investigated epidemiologically except by interview or questionnaire studies. Some recent examples illustrate the continuing problems of participation bias and recall bias.