Tandem Triplication 11p15.5-ICR1 (H19/IGF2) Detected by Microarray and Optical Genome Mapping in a Prenatal Beckwith-Wiedemann Case

Optical genome mapping (OGM) appears as a new tool for matching standard cytogenetic methods (karyotype and microarray) into a single assay. The chromosomal region 11p15.5 harbours two differentially methylated regions, the imprinting centre regions 1 and 2 (ICR1, ICR2). Disturbances in both regions alter human growth and are associated with two imprinting disorders, Beckwith-Wiedemann (BWS) and Silver-Russell syndromes. Herein, we present a prenatal case with a triplication in 11p15.5, including the H19/IGF2 imprinted region, detected by microarray and OGM. A 30-year-old pregnant woman of 17 weeks of gestation was referred for prenatal karyotype and microarray study because of increased nuchal translucency, short femur, megabladder, hyperechogenic bowel, and renal ectasia. Microarray, OGM, and MS-MLPA were performed, and a tandem cis-triplication in 11p15.5 and hypermethylation of the ICR1 region, compatible with BWS was detected. OGM, with its power to detect all classes of structural variants, including copy number variants, at a higher resolution than traditional cytogenetic methods can play a significant role in prenatal care and management as a next-generation cytogenomic tool. This study further supports the hypotheses that the amplification/duplication-triplication of the H19/IGF2 region could be related to BWS if it is of paternal origin.

Fetal Micro and Macroglossia: Defining Normal Fetal Tongue Size

OBJECTIVES

Abnormal fetal tongue size is a phenotypic feature of various syndromes including Beckwith-Wiedemann, Pierre-Robin, oromandibular limb hypoplasia, chromosomal aberrations, etc. Current data regarding normal fetal tongue size are limited. Hence, micro/macroglossia are subjectively determined. The aim of the study was to construct a contemporary fetal tongue nomogram and to assess its clinical contribution.

METHODS

A prospective cross-sectional study was performed in well dated, low risk, singleton pregnancies. Fetal tongues were measured by 5 trained sonographers. Highest quality images were selected. Intra- and interobserver variability was assessed. Tongue length, width, area, and circumference 1st to 99th centiles were calculated for each gestational week. Based on the normal tongue size charts, we created a Tongue Centile Calculator.

RESULTS

Over 18 months, 664 tongue measurements were performed. A cubic polynomial regression model best described the correlation between tongue size and gestational age. The correlation coefficient (r² ) was 0.934, 0.932, 0.925, and 0.953 for tongue length, width, area, and circumference, respectively (P < .001). Intra- and interobserver variability had high interclass correlation coefficients (>0.9). Using the new charts, we were able to identify 2 cases of macroglossia, subsequently diagnosed with Beckwith-Wiedemann, and 4 cases of microglossia, 3 associated with Pierre-Robin sequence, and 1 associated with persistent buccopharyngeal membrane.

CONCLUSIONS

We present novel fetal tongue size charts from 13 to 40 weeks of gestation. Clinical application of these nomograms may be beneficial in the prenatal diagnosis of syndromes or malformations associated with abnormal fetal tongue size.

Clinical Spectrum and Tumour Risk Analysis in Patients with Beckwith-Wiedemann Syndrome Due to CDKN1C Pathogenic Variants

Beckwith-Wiedemann syndrome spectrum (BWSp) is an overgrowth disorder caused by imprinting or genetic alterations at the 11p15.5 locus. Clinical features include overgrowth, macroglossia, neonatal hypoglycaemia, omphalocele, hemihyperplasia, cleft palate, and increased neoplasm incidence. The most common molecular defect observed is hypomethylation at the imprinting centre 2 (KCNQ1OT1:TSS DMR) in the maternal allele, which accounts for approximately 60% of cases, although CDKN1C pathogenic variants have been reported in 5-10% of patients, with a higher incidence in familial cases. In this study, we examined the clinical and molecular features of all cases of BWSp identified by the Spanish Overgrowth Registry Initiative with pathogenic or likely pathogenic CDKN1C variants, ascertained by Sanger sequencing or next-generation sequencing, with special focus on the neoplasm incidence, given that there is scarce knowledge of this feature in CDKN1C-associated BWSp. In total, we evaluated 21 cases of BWSp with CDKN1C variants; 19 were classified as classical BWS according to the BWSp scoring classification by Brioude et al. One of our patients developed a mediastinal ganglioneuroma. Our study adds evidence that tumour development in patients with BWSp and CDKN1C variants is infrequent, but it is extremely relevant to the patient's follow-up and supports the high heterogeneity of BWSp clinical features associated with CDKN1C variants.

A patient with multilocus imprinting disturbance involving hypomethylation at 11p15 and 14q32, and phenotypic features of Beckwith-Wiedemann and Temple syndromes

Beckwith‐Wiedemann syndrome (BWS) and Temple syndrome (TS) are classical imprinting disorders (IDs) with nonconfluent clinical features. We report here on a patient with clinical features of both syndromes, in whom epimutations were found at the BWS and TS imprinted regions, consistent with multilocus imprinting disturbance (MLID). This is the first case report of a patient with clinical features of both conditions who was found to have loss of methylation (LOM) of KCNQ1OT1: TSS‐DMR (ICR2) in the 11p15 imprinted region associated with BWS and LOM of MEG3: TSS‐DMR in the 14q32 imprinted region associated with TS. The report draws attention to the importance of testing for MLID as a cause of atypical clinical presentations of patients with IDs.

Multi-locus imprinting disturbances of Beckwith-Wiedemann and Large offspring syndrome/Abnormal offspring syndrome: A brief review

In vitro fertilization and somatic cell nuclear transfer are assisted reproduction technologies commonly used in humans and cattle, respectively. Despite advances in these technologies, molecular failures can occur, increasing the chance of the onset of imprinting disorders in the offspring. Large offspring syndrome/abnormal offspring syndrome (LOS/AOS) has been described in cattle and has features such as hypergrowth, malformation of organs, and skeletal and placental defects. In humans, Beckwith-Wiedemann syndrome (BWS) has phenotypic characteristics similar to those found in LOS/AOS. In both syndromes, disruption of genomic imprinting associated with loss of parental-specific expression and parental-specific epigenetic marks is involved in the molecular etiology. Changes in the imprinting pattern of these genes lead to loss of imprinting (LOI) due to gain or loss of methylation, inducing the emergence of these syndromes. Several studies have reported locus-specific alterations in these syndromes, such as hypomethylation in imprinting control region 2 (KvDMR1) in BWS and LOS/AOS. These LOI events can occur at multiple imprinted loci in the same affected individual, which are called multi-locus methylation defect (MLMD) events. Although the bovine species has been proposed as a developmental model for human imprinting disorders, there is little information on bovine imprinted genes in the literature, even the correlation of epimutation data with clinical characteristics. In this study, we performed a systematic review of all the multi-locus LOI events described in human BWS and LOS/AOS, in order to determine in which imprinted genes the largest changes in the pattern of DNA methylation and expression occur, helping to fill gaps for a better understanding of the etiology of both syndromes.

A Case report: Co-occurrence of IMAGe syndrome and Rhabdomyosarcoma

IMAGe syndrome is a rare congenital disorder, presenting with intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita and genital anomalies (in males). So far only 17 individuals have been diagnosed molecularly with IMAGe syndrome, this patient is the first case of an individual diagnosed with IMAGe and concurrent rhabdomyosarcoma. The patient was born at 30 weeks' gestation and received treatment for hyponatremia and hyperkalemia. At 4 9/12 years of age the patient showed a painless, non-mobile mass on the left thigh. In the biopsy performed a sarcoma weave with solid, nest-like growth, with characteristics of rhabdomyosarcoma was identified. The family history and physical examination indicated IMAGe syndrome so genetic testing was requested. A whole exome sequencing procedure with use of SureSelectXT Human ALL Exon V7, confirmed a single nucleotide variant NM_000076.2(CDKN1C):c.820G>A (p.Asp274Asn); identifying a missense mutation in the imprinted gene CDKN1C associated with IMAGe syndrome. Although tumours associated with CDKN1C are rare, deregulation of imprinted genes is increasingly being recognised as a mechanism of tumorigenesis in cancer; chromosomal region 11p15.5 contains a cluster of imprinted genes. This same region is the most consistent site of allele loss in rhabdomyosarcoma and is the same region altered in both IMAGe and Beckwith-Wiedemann syndrome. Molecular studies have found genetic changes in the 11p15 region in a variety of embryonal tumours like Wilms tumours which are commonly developed in Beckwith-Wiedemann syndrome and embryonal rhabdomyosarcoma. Through this case we aim to present the possibility of oncogenesis in patients with IMAGe syndrome, specifically rhabdomyosarcoma.

Overgrowth Syndromes-Evaluation, Diagnosis, and Management

Abnormally excessive growth results from perturbation of a complex interplay of genetic, epigenetic, and hormonal factors that orchestrate human growth. Overgrowth syndromes generally present with inherent health concerns and, in some instances, an increased risk of tumor predisposition that necessitate prompt diagnosis and appropriate referral. In this review, we introduce some of the more common overgrowth syndromes, along with their molecular mechanisms, diagnostics, and medical complications for improved recognition and management of patients affected with these disorders.

Corrigendum: Overgrowth Syndromes-Evaluation, Diagnosis, and Management

[This corrects the article DOI: 10.3389/fped.2020.574857.].

Adrenocortical adenoma in a Sudanese girl with Beckwith-Wiedemann syndrome

Background

We report a case of right adrenocortical adenoma in a girl with features suggestive of Beckwith Wiedemann syndrome to show the importance of tumor surveillance in patients with Beckwith Wiedemann syndrome.

Case presentation

A 4-years-old female with features suggestive of Beckwith-Wiedemann syndrome presented with 9 months history of virilization. Hormonal investigations results showed high levels of testosterone (2.3 ng/ml, normal values 0.1-0.4 ng/ml), and DHEAS (73 ng/ml normal values 1-6 ng/ml) with normal cortisol level. Computed tomography revealed a right adrenal mass. She underwent right adrenalectomy. Histopathological examination of the resected adrenal gland showed adrenocortical adenoma. Her postoperative evaluation showed a normal testosterone level.

Conclusion

Adrenocortical neoplasms though rare in children are well documented in Beckwith-Wiedemann syndrome patients. So tumor surveillance protocol should be employed, even in a resource-limited setting for early tumor detection and a better outcome.

Whole-Exome Sequencing of Syndromic Adrenocortical Carcinoma Reveals Distinct Mutational Profile From Sporadic ACC

Next-generation sequencing has provided genetic profiles of a large number of sporadic adrenocortical carcinomas (ACCs), but the applicability of these results to ACC cases associated with tumor predisposition syndromes is unclear. Although the germline features of these syndromes have been well described, the somatic mutational landscape of the tumors they give rise to is less clear. Our group obtained germline and tumor tissue from a pediatric patient who developed ACC during her first year of life, which was treated successfully. She was subsequently diagnosed with additional tumors later in childhood. Whole exome sequencing analysis was performed followed by in silico protein function prediction, revealing a probably deleterious germline TP53 L265P mutation. The somatic mutational burden was comparable between the index case and a previously published cohort of 40 sporadic cases, but the mutational spectrum was distinct in terms of raw base-change frequency as well as in a trinucleotide context-specific analysis. No canonical somatic genetic drivers of ACC were identified in the reported case, suggesting that syndromic adrenocortical tumors may represent a genetically distinct entity from sporadic tumors.

Defining an optimal time window to screen for hepatoblastoma in children with Beckwith-Wiedemann syndrome

Patients with Beckwith-Wiedemann spectrum (BWSp) undergo quarterly alpha-fetoprotein measurement for hepatoblastoma (HB) screening up to 4 years of age, paralleling the epidemiology of nonsyndromic HB. However, specific data on the timing of HB development in BWSp are lacking. Here we compare the timing of presentation of HBs in BWSp with a control cohort of consecutive HB cases, demonstrating that halving screening duration of screening procedures in BWSp likely will not impact its effectiveness.

Hyperinsulinemic hypoglycemia in Beckwith-Wiedemann, Sotos, and Kabuki syndromes: A nationwide survey in Japan

Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth syndrome that is occasionally associated with hyperinsulinemic hypoglycemia (HH) in the neonatal period. Sotos syndrome (SS) and Kabuki syndrome (KS) are other malformation syndromes that may be complicated with HH, however, the detailed clinical characteristics of HH accompanied with these syndromes remain unclear. We herein conducted a nationwide questionnaire survey in Japan. We sent a primary questionnaire concerning the clinical experience for these syndromes to 347 perinatal care institutions. As a result, 222 departments or hospitals returned the questionnaires and the total numbers of BWS, SS, and KS patients were 113, 88, and 51, respectively. We sent a secondary questionnaire to 31 institutions where patients with these syndromes presented with HH during infancy. The secondary questionnaires were returned from the institutions and the numbers of patients were 16 for BWS, 9 for SS, and 3 for KS, respectively. Then, we compared the clinical characteristics of infants suffering from transient HH with and without these dysmorphic syndromes. As a result, BWS, SS, and KS patients showed significantly larger body size, lower Apgar scores, higher insulin levels at HH, and shorter durations of HH than non-dysmorphic infants with transient HH. We propose that a careful observation for the signs of HH, even if not specific to the syndromes, is important for the diagnosis of patients with BWS, SS, and KS in the postnatal period. © 2016 Wiley Periodicals, Inc.

Cancer Risk in Beckwith-Wiedemann Syndrome: A Systematic Review and Meta-Analysis Outlining a Novel (Epi)Genotype Specific Histotype Targeted Screening Protocol

OBJECTIVE

To compare tumor risk in the 4 Beckwith-Wiedemann syndrome (BWS) molecular subgroups: Imprinting Control Region 1 Gain of Methylation (ICR1-GoM), Imprinting Control Region 2 Loss of Methylation (ICR2-LoM), Chromosome 11p15 Paternal Uniparental Disomy (UPD), and Cyclin-Dependent Kinase Inhibitor 1C gene (CDKN1C) mutation.

STUDY DESIGN

Studies on BWS and tumor development published between 2000 and 2015 providing (epi)genotype-cancer correlations with histotype data were reviewed and meta-analysed with cancer histotypes as measured outcome and (epi)genotype as exposure.

RESULTS

A total of 1370 patients with BWS were included: 102 developed neoplasms (7.4%). Tumor prevalence was 2.5% in ICR2-LoM, 13.8% in UPD, 22.8% in ICR1-GoM, and 8.6% in patients with CDKN1C mutations. Cancer ORs were 12.8 in ICR1-GoM, 6.5 in UPD, and 2.9 in patients with CDKN1C mutations compared with patients with ICR2-LoM. Wilms tumor was associated with ICR1-GoM (OR 68.3) and UPD (OR 13.2). UPD also was associated with hepatoblastoma (OR 5.2) and adrenal carcinoma (OR 7.0), and CDKN1C mutations with neuroblastic tumors (OR 7.2).

CONCLUSION

Cancer screening in BWS could be differentiated on the basis of (epi)genotype and target specific histotypes. Patients with ICR1-GoM and UPD should undergo renal ultrasonography scanning, given their risk of Wilms tumor. Alpha feto protein monitoring for heptaoblastoma is suggested in patients with UPD. Adrenal carcinoma may deserve screening in patients with UPD. Patients with CDKN1C mutations may deserve neuroblastoma screening based on urinary markers and ultrasonography scanning. Finally, screening appears questionable in cases of ICR2-LoM, given low tumor risk.

Fetal growth patterns in Beckwith-Wiedemann syndrome

We provide data on fetal growth pattern on the molecular subtypes of Beckwith-Wiedemann syndrome (BWS): IC1 gain of methylation (IC1-GoM), IC2 loss of methylation (IC2-LoM), 11p15.5 paternal uniparental disomy (UPD), and CDKN1C mutation. In this observational study, gestational ages and neonatal growth parameters of 247 BWS patients were compared by calculating gestational age-corrected standard deviation scores (SDS) and proportionality indexes to search for differences among IC1-GoM (n = 21), UPD (n = 87), IC2-LoM (n = 147), and CDKN1C mutation (n = 11) patients. In IC1-GoM subgroup, weight and length are higher than in other subgroups. Body proportionality indexes display the following pattern: highest in IC1-GoM patients, lowest in IC2-LoM/CDKN1C patients, intermediate in UPD ones. Prematurity was significantly more prevalent in the CDKN1C (64%) and IC2-LoM subgroups (37%). Fetal growth patterns are different in the four molecular subtypes of BWS and remarkably consistent with altered gene expression primed by the respective molecular mechanisms. IC1-GoM cases show extreme macrosomia and severe disproportion between weight and length excess. In IC2-LoM/CDKN1C patients, macrosomia is less common and associated with more proportionate weight/length ratios with excess of preterm birth. UPD patients show growth patterns closer to those of IC2-LoM, but manifest a body mass disproportion rather similar to that seen in IC1-GoM cases.

Mutations of the Imprinted CDKN1C Gene as a Cause of the Overgrowth Beckwith-Wiedemann Syndrome: Clinical Spectrum and Functional Characterization

Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder associating macroglossia, abdominal wall defects, visceromegaly, and a high risk of childhood tumor. Molecular anomalies are mostly epigenetic; however, mutations of CDKN1C are implicated in 8% of cases, including both sporadic and familial forms. We aimed to describe the phenotype of BWS patients with CDKN1C mutations and develop a functional test for CDKN1C mutations. For each propositus, we sequenced the three exons and intron-exon boundaries of CDKN1C in patients presenting a BWS phenotype, including abdominal wall defects, without 11p15 methylation defects. We developed a functional test based on flow cytometry. We identified 37 mutations in 38 pedigrees (50 patients and seven fetuses). Analysis of parental samples when available showed that all mutations tested but one was inherited from the mother. The four missense mutations led to a less severe phenotype (lower frequency of exomphalos) than the other 33 mutations. The following four tumors occurred: one neuroblastoma, one ganglioneuroblastoma, one melanoma, and one acute lymphoid leukemia. Cases of BWS caused by CDKN1C mutations are not rare. CDKN1C sequencing should be performed for BWS patients presenting with abdominal wall defects or cleft palate without 11p15 methylation defects or body asymmetry, or in familial cases of BWS.

(Epi)genotype-phenotype correlations in Beckwith-Wiedemann syndrome: a paradigm for genomic medicine

Beckwith-Wiedemann syndrome (BWS) is the commonest overgrowth cancer predisposition disorder and represents a model for human imprinting dysregulation and tumorigenesis. BWS features can variably combine and present a widely variable range of severity in the phenotypic expression. This wide spectrum is paralleled at molecular level by complex (epi)genetic defects on chromosome 11p15.5 leading to disrupted expression of imprinted genes controlling growth and cellular proliferation. In this review, we outline the spectrum of clinical manifestations of BWS analyzing their (epi)genotype-phenotype correlations. The differences observed in the phenotypic profiles of BWS molecular subtypes allow a composite view of this syndrome with implications on clinical care, diagnosis, follow-up, and management, and provide directions for future disease monitoring.

Mosaic paternal genome-wide uniparental isodisomy with down syndrome

We report on a 6-month-old girl with two apparent cell lines; one with trisomy 21, and the other with paternal genome-wide uniparental isodisomy (GWUPiD), identified using single nucleotide polymorphism (SNP) based microarray and microsatellite analysis of polymorphic loci. The patient has Beckwith-Wiedemann syndrome (BWS) due to paternal uniparental disomy (UPD) at chromosome location 11p15 (UPD 11p15), which was confirmed through methylation analysis. Hyperinsulinemic hypoglycemia is present, which is associated with paternal UPD 11p15.5; and she likely has medullary nephrocalcinosis, which is associated with paternal UPD 20, although this was not biochemically confirmed. Angelman syndrome (AS) analysis was negative but this testing is not completely informative; she has no specific features of AS. Clinical features of this patient include: dysmorphic features consistent with trisomy 21, tetralogy of Fallot, hemihypertrophy, swirled skin hyperpigmentation, hepatoblastoma, and Wilms tumor. Her karyotype is 47,XX,+21[19]/46,XX[4], and microarray results suggest that the cell line with trisomy 21 is biparentally inherited and represents 40-50% of the genomic material in the tested specimen. The difference in the level of cytogenetically detected mosaicism versus the level of mosaicism observed via microarray analysis is likely caused by differences in the test methodologies. While a handful of cases of mosaic paternal GWUPiD have been reported, this patient is the only reported case that also involves trisomy 21. Other GWUPiD patients have presented with features associated with multiple imprinted regions, as does our patient.

Twenty-one years to the right diagnosis - clinical overlap of Simpson-Golabi-Behmel and Beckwith-Wiedemann syndrome

Clinical overlap makes the diagnosis of overgrowth syndromes challenging. Clinical overlap exists between Simpson-Golabi-Behmel syndrome (SGBS) and Beckwith-Wiedemann syndrome (BWS) which share pre- and postnatal overgrowth, macroglossia, umbilical hernia, organomegaly, ear lobe creases, and occurrence of embryonal tumors as characteristic features. Based on the clinical history of a patient, who was diagnosed with BWS shortly after birth and reassessed and rediagnosed with SGBS at age 21 years, particular attention should be paid to developing facial dysmorphia. In addition, we delineate further clinical findings that may allow differentiation between both conditions.

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.

Clinical features of three girls with mosaic genome-wide paternal uniparental isodisomy

Here we describe three subjects with mosaic genome-wide paternal uniparental isodisomy (GWpUPD) each of whom presented initially with overgrowth, hemihyperplasia (HH), and hyperinsulinism (HI). Due to the severity of findings and the presence of additional features, SNP array testing was performed, which demonstrated mosaic GWpUPD. Comparing these individuals to 10 other live-born subjects reported in the literature, the predominant phenotype is that of pUPD11 and notable for a very high incidence of tumor development. Our subjects developed non-metastatic tumors of the adrenal gland, kidney, and/or liver. All three subjects had pancreatic hyperplasia resulting in HI. Notably, our subjects to date display minimal features of other diseases associated with paternal UPD loci. Both children who survived the neonatal period have displayed near-normal cognitive development, likely due to a favorable tissue distribution of the mosaicism. To understand the range of UPD mosaicism levels, we studied multiple tissues using SNP array analysis and detected levels of 5-95%, roughly correlating with the extent of tissue involvement. Given the rapidity of tumor growth and the difficulty distinguishing malignant and benign tumors in these GWpUPD subjects, we have utilized increased frequency of ultrasound (US) and alpha-fetoprotein (AFP) screening in the first years of life. Because of a later age of onset of additional tumors, continued tumor surveillance into adolescence may need to be considered in these rare patients.