Beckwith-Wiedemann syndrome. An update and review for the primary pediatrician

Assessment of the tongue frenulum in Beckwith-Wiedemann syndrome: Pre- and post-frenectomy findings

AIM

To report the pre- and post-frenectomy findings of a patient with Beckwith-Wiedemann syndrome.

METHODS AND RESULTS

Clinical case report of a patient with a confirmed genetic-molecular diagnosis of the referred syndrome. The minor was evaluated and reassessed by the protocol for the evaluation of the tongue's frenulum for babies in two moments: pre-surgical and 2 months after the frenectomy. The surgical procedure was performed using the traditional technique and, after the procedure, the minor was breastfed and received photobiomodulation with a red laser. The minor obtained 16 points in the neonatal tongue screening test, indicating the need for a frenectomy. Thus, she was referred to a dentist for surgery. After the surgical procedure, macroglossia was observed as a maternal complaint (previously not mentioned). The wound healing was satisfactory, and the total score obtained in the reapplication of the protocol (five points) showed functional results of improvements in sucking and tongue mobility, justifying the importance of the frenectomy.

CONCLUSION

Frenectomy, despite showing macroglossia related to the Beckwith-Wiedemann syndrome, allowed anatomical and functional advances of the tongue in the present clinical case.

Preclinical and Clinical Epigenetic-Based Reconsideration of Beckwith-Wiedemann Syndrome

Epigenetics has achieved a profound impact in the biomedical field, providing new experimental opportunities and innovative therapeutic strategies to face a plethora of diseases. In the rare diseases scenario, Beckwith-Wiedemann syndrome (BWS) is a pediatric pathological condition characterized by a complex molecular basis, showing alterations in the expression of different growth-regulating genes. The molecular origin of BWS is associated with impairments in the genomic imprinting of two domains at the 11p15.5 chromosomal region. The first domain contains three different regions: insulin growth like factor gene (IGF2), H19, and abnormally methylated DMR1 region. The second domain consists of cell proliferation and regulating-genes such as CDKN1C gene encoding for cyclin kinase inhibitor its role is to block cell proliferation. Although most cases are sporadic, about 5-10% of BWS patients have inheritance characteristics. In the 11p15.5 region, some of the patients have maternal chromosomal rearrangements while others have Uniparental Paternal Disomy UPD(11)pat. Defects in DNA methylation cause alteration of genes and the genomic structure equilibrium leading uncontrolled cell proliferation, which is a typical tumorigenesis event. Indeed, in BWS patients an increased childhood tumor predisposition is observed. Here, we summarize the latest knowledge on BWS and focus on the impact of epigenetic alterations to an increased cancer risk development and to metabolic disorders. Moreover, we highlight the correlation between assisted reproductive technologies and this rare disease. We also discuss intriguing aspects of BWS in twinning. Epigenetic therapies in clinical trials have already demonstrated effectiveness in oncological and non-oncological diseases. In this review, we propose a potential "epigenetic-based" approaches may unveil new therapeutic options for BWS patients. Although the complexity of the syndrome is high, patients can be able to lead a normal life but tumor predispositions might impair life expectancy. In this sense epigenetic therapies should have a supporting role in order to guarantee a good prognosis.

Successful use of long acting octreotide in two cases with Beckwith-Wiedemann syndrome and severe hypoglycemia

INTRODUCTION

Hyperinsulinism associated with Beckwith-Wiedemann syndrome (BWS) can occur in about 50% of cases, causing hypoglycemia of variable severity. Parenteral use of octreotide may be indicated if unresponsive to diazoxide. There is limited data on use of octreotide in BWS.

OBJECTIVE

Chart review describing 2 cases with BWS and hypoglycemia treated with long acting Octreotide as a monthly injection.

CASES

We describe two unrelated females born large for gestational age found to have clinical features consistent with BWS, who developed severe hypoglycemia. Genetic diagnosis of BWS was confirmed. The first patient was born at 37 weeks and developed hypoglycemia shortly after birth. She was initially started on diazoxide but developed pulmonary congestion and was therefore switched to depot octreotide (LAR). She maintained euglycemia with LAR. In the second patient (born at 26-4/7 weeks), onset of hypoglycemia was delayed till 11 weeks of age due to hydrocortisone (indicated hemodynamically) and continuous feeding, and was partially responsive to diazoxide. She was switched to octreotide 4 times daily, treated till at age 18 months. Despite frequent feeds, she required treatment again between ages 4-6.5 years, initially with diazoxide but due to severe hypertrichosis she was switched to LAR with an excellent response. Both patients treated with LAR for over two years achieved euglycemia above 70 mg/dl and had normal height gain, without side effects.

CONCLUSION

Successful treatment of hypoglycemia can be achieved and maintained with LAR in infants and children with BWS who are either resistant or cannot tolerate diazoxide.

Psychosocial, feeding, and drooling outcomes in children with Beckwith Wiedemann syndrome following tongue reduction surgery

OBJECTIVE

Macroglossia is a common feature of Beckwith Wiedemann Syndrome (BWS). Tongue reduction surgery (TRS) is advocated to overcome, or reduce, the secondary effects of macroglossia. Macroglossia may affect a child's cosmetic appearance, feeding, and drooling function. However, no study has systematically reported on feeding, drooling, or psychosocial outcomes preoperatively and postoperatively in this group. This study aimed to describe the presurgical and postsurgical psychosocial, feeding, and drooling outcomes of children with macroglossia associated with BWS and to determine the effect of TRS on these areas.

DESIGN

Clinical cohort study.

PARTICIPANTS

Ten consecutively admitted children with BWS (age at surgery from 9 months to 4 years, 9 months [4;9]; mean, 2;7) were assessed preoperatively, 3 months postoperatively, and at long-term follow-up.

MAIN OUTCOME MEASURES

A parental report questionnaire, the Brodsky drooling scale, and a feeding rating scale.

RESULTS

Parents reported that macroglossia had a negative impact cosmetically that was ameliorated following surgery. Macroglossia caused a range of feeding difficulties presurgically by preventing lip seal and bolus manipulation during the oral preparatory phase. Excessive drooling was present in all cases presurgically. This resolved partially across the group postsurgically, with almost complete recovery at longer-term follow-up assessment.

CONCLUSIONS

Presurgically, children show a common profile of feeding and drooling impairment with negative effects on cosmetic appearance. Our preliminary results demonstrate that TRS has a positive impact on these features with good outcomes for children with 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.

Unusual renal pathology associated with a Wilms tumor in a 15-month-old infant

Beckwith-Wiedemann syndrome is an overgrowth dis-order that predisposes to the development of a variety of malignancies including Wilms tumor. Pathologists may suspect the presence of Beckwith-Wiedemann syndrome, which may be clinically subtle, on the basis of the histopathology of the renal parenchyma adjacent to a Wilms tumor. These kidneys typically harbor multiple nephrogenic rests (especially perilobar nephrogenic rests), and their medullas have blunted papillae resulting from excessive fibromyxoid stroma, decreased collecting ducts, and decreased Henle loops. This complex of findings constitutes the so-called Beckwith Medulla. Extensions of this stroma-rich medulla into the cortex results in characteristic dysplastic medullary-ray nodules. Identification of these histologic abnormalities by the pathologist should prompt the clinician to evaluate the child for Beckwith-Wiedemann syndrome. Proper screening of these children can allow for early detection of cancers and treatment while these cancers are curable.

Macroglossia: a case study

A young child with macroglossia of unknown cause was seen for treatment to modify resting tongue posture and improve speech sound production. Evaluation of the treatments indicated positive change in resting tongue posture and a modest change in speech sound production. Treatment for such patients can be complex and must consider orthodontic and/or surgical interventions, because an enlarged tongue can influence growth, development, and physiology of the oropharyngeal complex. The speech-language pathologist must be prepared to deal with the complex of problems demonstrated by patients with macroglossia during growth and development.

LEARNING OUTCOMES

(1) As a result of this activity, the participant will be able to describe the sequelae of macroglossia. (2) As a result of this activity, the participant will be able to identify appropriate treatment options for children with macroglossia.

Anesthesia in Beckwith-Wiedemann syndrome

Anesthetic management of a 3-month-old boy with Beckwith-Wiedemann syndrome for bronchoscopy is reported. Management may be complicated by a difficult airway, congenital heart disease, and hypoglycemia. We did not have difficulty in airway management either with tracheal intubation or rigid bronchoscopy, but we could not extubate the baby because of tracheomalacia.

Hyperinsulinism in Infancy: From Basic Science to Clinical Disease

Dunne, Mark J., Karen E. Cosgrove, Ruth M. Shepherd, Albert Aynsley-Green, and Keith J. Lindley. Hyperinsulinism in Infancy: From Basic Science to Clinical Disease. Physiol Rev 84: 239–275, 2004; 10.1152/physrev.00022.2003.—Ion channelopathies have now been described in many well-characterized cell types including neurons, myocytes, epithelial cells, and endocrine cells. However, in only a few cases has the relationship between altered ion channel function, cell biology, and clinical disease been defined. Hyperinsulinism in infancy (HI) is a rare, potentially lethal condition of the newborn and early childhood. The causes of HI are varied and numerous, but in almost all cases they share a common target protein, the ATP-sensitive K+channel. From gene defects in ion channel subunits to defects in β-cell metabolism and anaplerosis, this review describes the relationship between pathogenesis and clinical medicine. Until recently, HI was generally considered an orphan disease, but as parallel defects in ion channels, enzymes, and metabolic pathways also give rise to diabetes and impaired insulin release, the HI paradigm has wider implications for more common disorders of the endocrine pancreas and the molecular physiology of ion transport.

Presence of vascular anomalies with congenital hemihypertrophy and Wilms tumor: an evidence-based evaluation

Congenital hemihypertrophy is an uncommon condition of unknown etiology characterized by unilateral overgrowth of part or all of one side of the body. Hemihypertrophy is known to be associated with certain childhood tumors, most notably Wilms tumor (or nephroblastoma), and for this reason infants with hemihypertrophy are often followed with serial abdominal ultrasounds. Klippel-Trénaunay syndrome (KTS) is the triad of port-wine stain, venous varicosities, and soft tissue and/or bony hypertrophy. Children with KTS typically have localized rather than generalized hemihypertrophy, but occasionally the hypertrophy is more extensive than the vascular anomaly itself. Information is lacking about whether hemihypertrophy in this setting can also be a risk factor for Wilms tumor. We systematically reviewed the medical literature to determine whether well-documented cases of Wilms tumor in the setting of both hemihypertrophy and vascular anomalies have been described, and if found, whether the association was sufficiently frequent that routine screening for Wilms tumor in this setting should be recommended. A review of case reports and case series in the pediatric population was undertaken using specific inclusion and exclusion criteria. We found 4 of 58 subjects with hemihypertrophy and Wilms tumor had a reported vascular anomaly, but in only one case was a clear-cut diagnosis of KTS confirmed. The relationship of the other three vascular anomalies reported was of uncertain significance. In conclusion, our review suggests that the risk of Wilms tumor in the setting of localized soft-tissue hypertrophy in conjunction with a vascular malformation is quite low. More extensive hemihypertrophy extending to body sites remote from the vascular malformation itself could have a higher risk of Wilms tumor, although the magnitude of this risk is uncertain. Our findings suggest that routine serial abdominal ultrasounds in patients with vascular malformations in association with localized soft-tissue hypertrophy are unwarranted.

The contribution of in vivo manipulation of gene expression to the understanding of the function of glypicans

The name glypican identifies a family of heparan sulfate proteoglycans that are linked to the cell surface by a glycosylphosphatidylinositol anchor. Members of this family have been identified in Drosophila, zebrafish, and mammals. The interest in the study of glypicans has increased in the last few years as a result of the discovery that the glypican-3 gene (GPC-3) is mutated in an overgrowth and dysmorphic syndrome. Despite the increased interest, our knowledge about the function of glypicans is still limited, since the molecular basis for the role of glypican-3 in the regulation of body size remains unknown. The in vivo manipulation of glypican expression in lower organisms, however, has demonstrated that these proteoglycans can modulate cellular responses to Wnts and bone morphogenetic factors. Future studies should investigate whether the phenotype of GPC-3-deficient individuals is also due to altered modulation of cellular responses to these factors.

Ectopic spleen and left-sided vena cava in Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth syndrome characterized by anterior abdominal wall defects, macroglossia, and gigantism. A variety of other abnormalities have been described, however association with ectopic spleen and left-sided vena cava has not been reported previously. We report ectopic spleen, left-sided vena cava and the other abdominal imaging findings of an adult BWS case who came up to date without any follow-up from the early childhood.

Overgrowth of a mouse model of the Simpson-Golabi-Behmel syndrome is independent of IGF signaling

The type 1 Simpson-Golabi-Behmel overgrowth syndrome (SGBS1) is caused by loss-of-function mutations of the X-linked GPC3 gene encoding glypican-3, a cell-surface heparan sulfate proteoglycan that apparently plays a negative role in growth control by an unknown mechanism. Mice carrying a Gpc3 gene knockout exhibited several phenotypic features that resemble clinical hallmarks of SGBS1, including somatic overgrowth, renal dysplasia, accessory spleens, polydactyly, and placentomegaly. In Gpc3/DeltaH19 double mutants (lacking GPC3 and also carrying a deletion around the H19 gene region that causes bialellic expression of the closely linked Igf2 gene by imprint relaxation), the Gpc3-null phenotype was exacerbated, while additional SGBS1 features (omphalocele and skeletal defects) were manifested. However, results from a detailed comparative analysis of growth patterns in double mutants lacking GPC3 and also IGF2, IGF1, or the type 1 IGF receptor (IGF1R) provided conclusive genetic evidence inconsistent with the hypothesis that GPC3 acts as a growth suppressor by sequestering or downregulating an IGF ligand. Nevertheless, our data are compatible with a model positing that there is downstream convergence of the independent signaling pathways in which either IGFs or (indirectly) GPC3 participate.

A less-invasive approach with orthodontic treatment in Beckwith-Wiedemann patients

The Beckwith-Wiedemann syndrome (BWS) is a rare genetic disorder, linked to an alteration on the short arm of chromosome 11 that comprises multiple congenital anomalies. Macroglossia is the predominant finding, with subsequent protrusion of dentoalveolar structures, which results in a protruding mandible, anterior open bite, abnormally obtuse gonial angle and increased mandibular length. A less-invasive treatment with orthopaedic appliances in a patient with early tongue reduction is presented. This work summarizes the oral signs linked to macroglossia, and highlights the influence of macroglossia on mandibular growth structures. In our opinion, glossotomy could be carried out in the paediatric patient as a preventive measure in that it curbs the tongue's influence on skeletal growth and dramatically reduces the duration and extensiveness of subsequent treatment.

Hypoglycemia in infants and children

Hypoglycemia is more common in the pediatric patient than in adults. This article discusses the many diagnoses that can be associated with hypoglycemia in infancy and childhood. A guide to help practitioners evaluate such patients and suggested treatments for many of these disorders are provided. As genetic diagnosis continues to develop, it is anticipated that the list of specific disorders associated with hypoglycemia in infancy and childhood will increase.

Glypican-3-deficient mice exhibit developmental overgrowth and some of the abnormalities typical of Simpson-Golabi-Behmel syndrome

Glypicans are a family of heparan sulfate proteoglycans that are linked to the cell surface through a glycosyl-phosphatidylinositol anchor. One member of this family, glypican-3 (Gpc3), is mutated in patients with the Simpson-Golabi-Behmel syndrome (SGBS). These patients display pre- and postnatal overgrowth, and a varying range of dysmorphisms. The clinical features of SGBS are very similar to the more extensively studied Beckwith-Wiedemann syndrome (BWS). Since BWS has been associated with biallelic expression of insulin-like growth factor II (IGF-II), it has been proposed that GPC3 is a negative regulator of IGF-II. However, there is still no biochemical evidence indicating that GPC3 plays such a role.Here, we report that GPC3-deficient mice exhibit several of the clinical features observed in SGBS patients, including developmental overgrowth, perinatal death, cystic and dyplastic kidneys, and abnormal lung development. A proportion of the mutant mice also display mandibular hypoplasia and an imperforate vagina. In the particular case of the kidney, we demonstrate that there is an early and persistent developmental abnormality of the ureteric bud/collecting system due to increased proliferation of cells in this tissue element. The degree of developmental overgrowth of the GPC3-deficient mice is similar to that of mice deficient in IGF receptor type 2 (IGF2R), a well characterized negative regulator of IGF-II. Unlike the IGF2R-deficient mice, however, the levels of IGF-II in GPC3 knockouts are similar to those of the normal littermates.

Contribution of clinical teratologists and geneticists to the evaluation of the etiology of congenital malformations alleged to be caused by environmental agents: ionizing radiation, electromagnetic fields, microwaves, radionuclides, and ultrasound

Analysis of these six clinical problems demonstrates the value of a complete clinical evaluation of a child with congenital malformations by an experienced and well-trained physician who is familiar with the fields of developmental biology, teratology , epidemiology, and genetics. Too often, the entire emphasis is placed on epidemiological data that may be meager or insufficient for a rational conclusion when clinical findings that are readily available can provide definitive answers with regard to the etiology of a child's malformations or the merits of an environmental etiology.

Adrenal fusion

Fusion of the adrenal glands is a rare congenital anomaly. The six cases described here were encountered in 3537 pediatric-perinatal autopsy cases. A fused adrenal was always associated with multiple congenital anomalies, including major central nervous system malformations in four cases, renal agenesis in three cases, anomalies of internal genitalia in three cases, and complex cardiac anomalies in two cases. The fused adrenal had either a horseshoe or butterfly shape. Neither adrenal hypoplasia nor hyperplasia appeared to be present, and the histologic appearance of the fused adrenal was normal in all cases.

Mouse mutant embryos overexpressing IGF-II exhibit phenotypic features of the Beckwith-Wiedemann and Simpson-Golabi-Behmel syndromes

In mice, the imprinted Igf2 gene (expressed from the paternal allele), which encodes a growth-promoting factor (IGF-II), is linked closely to the reciprocally imprinted H19 locus on chromosome 7. Also imprinted (expressed from the maternal allele) is the Igf2r gene on chromsome 17 encoding the type 2 IGF receptor that is involved in degradation of excess IGF-II. Double mutant embryos carrying a deletion around the H19 region and also a targeted Igf2r allele, both inherited maternally, have extremely high levels of IGF-II (7- and 11-fold higher than normal in tissues and serum, respectively) as a result of biallelic Igf2 expression (imprint relaxation by deletion of H19-associated sequence) in combination with lack of the IGF2R-mediated IGF-II turnover. This excess of IGF-II causes somatic overgrowth, visceromegaly, placentomegaly, omphalocele, and cardiac and adrenal defects, which are also features of the Beckwith-Wiedemann syndrome (BWS), a genetically complex human disorder associated with chromosomal abnormalities in the 11p15.5 region where the IGF2 gene resides. In addition, the double mutant mouse embryos exhibit skeletal defects and cleft palate, which are manifestations observed frequently in the Simpson-Golabi-Behmel syndrome, another overgrowth disorder overlapping phenotypically, but not genetically, with BWS.

Genomic imprinting in disorders of growth

This review has briefly considered some of the vast amount of information that has been gathered on genomic imprinting and its role in PWS, AS, BWS and Russell-Silver syndrome. The pace of investigation into the phenomenon of imprinting will undoubtedly continue, because our understanding remains far from complete. Newer approaches to identifying imprinted genes based on their expression rather than their location are likely to uncover currently unknown genes. We can also look forward to more insight into the fascinating complexities of the imprinting process.