Syndromes and Disorders Associated with Omphalocele (I): Beckwith–Wiedemann Syndrome

Omphalocele and Cardiac Abnormalities-The Importance of the Association

Omphalocele is the most common ventral abdominal wall defect. Omphalocele is associated with other significant anomalies in up to 80% of cases, among which the cardiac ones are the most frequent. The aim of our paper is to highlight, through a review of the literature, the importance and frequency of association between the two malformations and what impact this association has on the management and evolution of patients with these pathologies. We reviewed the titles, the available abstracts, and the full texts of 244 papers from the last 23 years, from three medical databases, to extract data for our review. Due to the frequent association of the two malformations and the unfavorable effect of the major cardiac anomaly on the prognosis of the newborn, the electrocardiogram and echocardiography must be included in the first postnatal investigations. The timing of surgery for abdominal wall defect closure is mostly dictated by the cardiac defect severity, and usually the cardiac defect takes priority. After the cardiac defect is medically stabilized or surgically repaired, the omphalocele reduction and closure of the abdominal defect are performed in a more controlled setting, with improved outcomes. Compared to omphalocele patients without cardiac defects, children with this association are more likely to experience prolonged hospitalizations, neurologic, and cognitive impairments. Major cardiac abnormalities such as structural defects that require surgical treatment or result in developmental delay will significantly increase the death rate of patients with omphalocele. In conclusion, the prenatal diagnosis of omphalocele and early detection of other associated structural or chromosomal anomalies are of overwhelming importance, contributing to the establishment of antenatal and postnatal prognosis.

Detection of hypermethylation at H19DMR at amniocentesis in a fetus with overgrowth, distended abdomen and Beckwith-Wiedemann syndrome

OBJECTIVE

We present detection of hypermethylation at H19 differentially methylated region (DMR) at amniocentesis in a fetus with overgrowth, distended abdomen and Beckwith-Wiedemann syndrome (BWS).

CASE REPORT

A 31-year-old, gravida 2, para 1, woman was referred for genetic counseling at 22 weeks of gestation because of fetal overgrowth with fetal biometry equivalent to 24 weeks of gestation and a distended abdomen with an abdominal circumference equivalent to 26 weeks of gestation. She did not undergo any assisted reproductive technology during this pregnancy. Amniocentesis was performed at 23 weeks of gestation. Conventional cytogenetic analysis revealed a karyotype of 46,XX. Array comparative genomic hybridization analysis on the DNA extracted from uncultured amniocytes revealed no genomic imbalance. Methylation analysis on the DNA extracted from amniocytes revealed hypermethylation at H19DMR [imprinting center 1 (IC1)] and normal methylation at KvDMR1 (IC2). The methylation test confirmed the diagnosis of BWS in the fetus. The parents decided to continue the pregnancy. At 36 weeks of gestation, a 4000-g female baby was delivered with macroglossia, ear tags and creases, and an enlarged liver, consistent with the phenotype of BWS.

CONCLUSION

Prenatal diagnosis of fetal overgrowth should include a differential diagnosis of BWS, and methylation analysis of H19DMR (IC1) and KvDMR1 (IC2) is useful under such a circumstance.

Quantitative DNA Methylation Analysis and Epigenotype-Phenotype Correlations in Taiwanese Patients with Beckwith-Wiedemann Syndrome

Background: Beckwith-Wiedemann syndrome (BWS; OMIM 130650) is a rare overgrowth syndrome with tumor predisposition resulting from the abnormal expression or function of imprinted genes of the chromosome 11p15.5 imprinting gene cluster. The aim of this study was to identify the epigenotype-phenotype correlations of these patients using quantitative DNA methylation analysis. Methods: One hundred and four subjects with clinically suspected BWS were enrolled in this study. All of the subjects had been referred for diagnostic testing which was conducted using methylation profiling of H19-associated imprinting center (IC) 1 and KCNQ1OT1-associated IC2 in high-resolution melting analysis and methylation quantification with the MassARRAY assay. Correlations between the quantitative DNA methylation status and clinical manifestations of the enrolled subjects were analyzed. Results: Among the 104 subjects, 19 had IC2 hypomethylation, 2 had IC1 hypermethylation, and 10 had paternal uniparental disomy (pUPD). The subjects with IC2 hypomethylation were characterized by significantly more macroglossia but less hemihypertrophy compared to the subjects with pUPD (p < 0.05). For 19 subjects with IC2 hypomethylation, the IC2 methylation level was significantly different (p < 0.05) between the subjects with and without features including macroglossia (IC2 methylation level: 11.1% vs. 30.0%) and prenatal or postnatal overgrowth (8.5% vs. 16.9%). The IC2 methylation level was negatively correlated with birth weight z score (p < 0.01, n = 19) and birth height z score (p < 0.05, n = 13). For 36 subjects with clinically diagnosed BWS, the IC2 methylation level was negatively correlated with the BWS score (r = −0.592, p < 0.01). The IC1 methylation level showed the tendency of positive correlation with the BWS score without statistical significance (r = 0.137, p > 0.05). Conclusions: Lower IC2 methylation and higher IC1 methylation levels were associated with greater disease severity in the subjects with clinically diagnosed BWS. Quantitative DNA methylation analysis using the MassARRAY assay could improve the detection of epigenotype-phenotype correlations, which could further promote better genetic counseling and medical care for these patients.

Left congenital diaphragmatic hernia and gastroschisis in a term male infant

A term male infant was born to a healthy 24-year-old mother with antenatally diagnosed liver-up, left congenital diaphragmatic hernia (CDH) and gastroschisis. The infant was stabilised in the neonatal intensive care unit and then underwent primary repair of the CDH via left subcostal incision and silo placement for the gastroschisis. Serial silo reductions were started postoperatively and umbilical flap closure for the gastroschisis was performed on day of life 6. The patient was weaned from respiratory support, started on enteral feeds, and discharged home at 1 month of age. He was weaned from supplemental nasogastric feeds by 6 weeks of age and is currently well and thriving at 11 months of age.

Deletion of BAF250a affects oocyte epigenetic modifications and embryonic development

BRG1-associated factor 250a (BAF250a) is a component of the SWI/SNF adenosine triphosphate-dependent chromatin remodeling complex, which has been shown to control chromatin structure and transcription. BAF250a was reported to be a key component of the gene regulatory machinery in embryonic stem cells controlling self-renewal, differentiation, and cell lineage decisions. Here we constructed Baf250a^F/F ;Gdf9-cre (Baf250a^CKO ) mice to specifically delete BAF250a in oocytes to investigate the role of maternal BAF250a in female germ cells and embryo development. Our results showed that BAF250a deletion did not affect folliculogenesis, ovulation, and fertilization, but it caused late embryonic death. RNA sequencing analysis showed that the expression of genes involved in cell proliferation and differentiation, tissue morphogenesis, histone modification, and nucleosome remodeling were perturbed in Baf250a^CKO MII oocytes. We showed that covalent histone modifications such as H3K27me3 and H3K27ac were also significantly affected in oocytes, which may reduce oocyte quality and lead to birth defects. In addition, the DNA methylation level of Igf2r, Snrpn, and Peg3 differentially methylated regions was decreased in Baf250a^CKO oocytes. Quantitative real-time polymerase chain reaction analysis showed that the relative messenger RNA (mRNA) expression levels of Igf2r and Snrpn were significantly increased. The mRNA expression level of Dnmt1, Dnmt3a, Dnmt3l, and Uhrf1 was decreased, and the protein expression in these genes was also reduced, which might be the cause for impaired imprinting establishment. In conclusion, our results demonstrate that BAF250a plays an important role in oocyte transcription regulation, epigenetic modifications, and embryo development.

Gestational Outcomes of Pregnancies with Prenatally Detected Gastroschisis and Omphalocele

Objective: To evaluate and compare the outcomes of pregnancies with prenatally detected gastroschisis and omphalocele. Materials and Methods: We retrospectively evaluated prenatally detected gastroschisis and omphalocele cases. Cases were compared in terms of maternal demographic and clinical characteristics as well as pregnancy and neonatal outcomes. Results: This study consisted of 17 gastroschisis and 30 omphalocele cases. Only one case with gastroschisis was terminated due to additional severe limb deformities. Seventeen out of 30 cases of omphalocele were terminated for various reasons (56.7%). All patients with gastroschisis had surgical repair, while 8 out of 13 omphalocele cases had surgery. One patient with an omphalocele died after surgery due to sepsis. Six cases of gastroschisis also died in the neonatal period due to various reasons (6/16, 37.5%). Conclusion: Additional genetic disorders are more frequent in those with omphalocele cases, and they are more frequently terminated during gestation that the gastroschisis fetuses.

A review of genetic factors underlying craniorachischisis and omphalocele: Inspired by a unique trisomy 18 case

Very few cases of craniorachischisis (CRN) with concomitant omphalocele (OMP) in the setting of trisomy 18 are reported in literature. Solitary midline closure defects are estimated to be more prevalent in trisomy 18 compared to the general population. Neurulation defect comparisons include anencephaly 0-2% versus 0.0206%, spina bifida 1-3% versus 0.0350%, and encephalocele 0-2% versus 0.0082% [Parker et al. (2010); Birth Defects Research. Part A: Clinical and Molecular Teratology, 88:1008-1016; Springett et al. (2015); American Journal of Medical Genetics. Part A, 167A:3062-3069]. The solitary anterior malformation OMP has been reported as high as 6% with trisomy 18 [Springett et al. (2015); American Journal of Medical Genetics. Part A, 167A:3062-3069]. We report the third published case of CRN with concomitant OMP observed in a likely trisomy 18 fetus that screened positive by noninvasive prenatal screening. Furthermore, we review and analyze the current literature to augment understanding of the genetic basis for anterior and posterior closure defects such as CRN and OMP. Although the current genetic lexicon lacks any definitive association with the simultaneous defects presented, previous research elucidated various genes related to anterior or posterior closure interruption individually. By consolidating current research, the authors advance knowledge of interconnected genetic pathology and direct future genetic mapping efforts.

Comparison of Quantitative Analysis of Methylated Alleles Real-Time PCR and Methylation-Specific MLPA for Molecular Diagnosis of Beckwith-Wiedemann Syndrome

<b><i>Background/Aims:</i></b> Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth disorder predisposing to tumorigenesis caused by abnormal expression or function of imprinted genes of the chromosome 11p15.5 imprinting gene cluster. This real-time PCR-based assay determines the methylation status of a selected CpG island and has been proposed for use in high-throughput methylation analysis. <b><i>Methods:</i></b> Here, we use quantitative analysis of methylated alleles (QAMA) for the detection of methylation status of the KCNQ10T1 gene, in a region immediately upstream of the transcription initiation site, and the CTCF binding site 6, located approximately 2 kb upstream of the SmaI site currently used for clinical laboratory testing. We assayed a series of controls and patients diagnosed with BWS at two different loci at 11p15.5 to assess the diagnostic yield of QAMA PCR for clinical laboratory testing. <b><i>Results:</i></b> These results compare favorably with methylation-specific multiple ligation probe amplification (MS-MLPA) analysis at both differentially methylated region (DMR)1 and DMR2. There are several advantages of the QAMA PCR over MS-MLPA. The QAMA PCR is less labor-intensive and therefore more cost-effective and does not require dedicated analysis software. A second advantage is that the assay is amenable to high-throughput analysis. <b><i>Conclusions:</i></b> The small sample size reflects the rare nature of this epigenetic disorder, and the range of ages was quite wide, as was the degree of disease severity. Therefore, further validation with larger cohorts is warranted.

Accuracy and impact of prenatal diagnosis in infants with omphalocele

BACKGROUND

Associated anomalies in omphalocele are common, but to which extent these anomalies are diagnosed before or after birth is less well documented.

AIM

To investigate the different types of associated anomalies, long-term survival and the extent whether these are diagnosed pre- or postnatally in children with a prenatal diagnosis of omphalocele at a single institution.

MATERIALS AND METHODS

Retrospective review of all pregnancies with omphalocele managed and/or born at our institution between 2006 and 2016.

RESULTS

A total of 42 cases with prenatally diagnosed omphalocele were identified. Of those 14 (31%) decided to terminate the pregnancy (TOP). Of the remaining 28 that continued, 12 were giant omphaloceles. The overall mortality rate was 18, 25% for giant and 12% for non-giant omphaloceles. 64% had associated anomalies. Only 1/3 of these anomalies is diagnosed prenatally.

CONCLUSION

The rate of associated malformations that are diagnosed postnatally is high, but the majority was malformations with a minor clinical significance or impact on future health. Beckwith-Wiedemann syndrome was present only in cases of non-giant omphalocele in our cohort.

Beckwith-Wiedemann Syndrome Review: A Guide for the Neonatal Nurse

Beckwith-Wiedemann syndrome (BWS) is the most common pediatric overgrowth syndrome. Features characteristic of the BWS phenotype include both physical attributes, such as macroglossia, abdominal wall defects, gigantism, nevus flammeus, visceromegaly, and mid-face hypoplasia, as well as biochemical abnormalities such as hypoglycemia. It is essential for the neonatal nurse to be able to recognize BWS in the patient's early years of life because of the increased frequency of medical complications, malformations, and the increased risk of embryonic malignancies. This article focuses on the presentation of BWS as an aid to early detection.

Virginal breast hypertrophy in a patient with Beckwith-Wiedemann syndrome

Virginal breast hypertrophy is a multidisciplinary condition including surgical, pediatric, and endocrine/gynecological disciplines, and its successful diagnosis and management requires complex, team approach.

Sequence variants identification at the KCNQ1OT1:TSS differentially Methylated region in isolated omphalocele cases

Background

Omphalocele is a congenital midline ventral body wall defect that can exist as isolated malformation or as part of a syndrome. It can be considered one of the major and most frequent clinical manifestation of Beckwith-Wiedemann Syndrome (BWS) in case of loss of methylation at KCNQ1OT1: Transcription Star Site-Differentially Methylated Region (TSS-DMR) or in presence of CDKN1C mutations. The isolated form of the omphalocele accounts approximately for about the 14% of the total cases and its molecular etiology has never been fully elucidated.

Methods

Given the tight relationship with BWS, we hypothesized that the isolated form of the omphalocele could belong to the heterogeneous spectrum of the BWS associated features, representing an endophenotype with a clear genetic connection. We therefore investigated genetic and epigenetic changes affecting BWS imprinted locus at 11p15.5 imprinted region, focusing in particular on the KCNQ1OT1:TSS DMR.

Results

We studied 21 cases of isolated omphalocele detected during pregnancy or at birth and identified the following rare maternally inherited variants: i) the non-coding variant G > A at nucleotide 687 (NR_002728.3) at KCNQ1OT1:TSS-DMR, which alters the methylation pattern of the imprinted allele, in one patient; ii) the deletion c.624-629delGGCCCC at exon 1 of CDKN1C, with unknown clinical significance, in two unrelated cases.

Conclusions

Taken together, these findings suggest that KCNQ1OT1:TSS-DMR could be a susceptibility locus for the isolated omphalocele.

Electronic supplementary material

The online version of this article (10.1186/s12881-017-0470-z) contains supplementary material, which is available to authorized users.

[Prenatal diagnosis of abdominal wall defects]

Anterior abdominal wall defects (AAWD) correspond to a wide spectrum of congenital defects affecting 6.3/10,000 pregnancies. They have in common a closure defect of the anterior abdominal wall and can be fatal or expose the fetus and the neonate (NN) to many complications. This study was based on a retrospective study of 22 cases of AAWD collected between May 2009 and December 2014. Its purpose was to specify the importance of prenatal ultrasonography in the diagnosis and prognosis assessment of these defects. These 22 AAWDs consisted in 13 cases of omphalocele (including four cases of Beckwith-Wiedemann syndrome), four of gastroschisis, one of pentalogy of Cantrell, three of vesical exstrophy and one of cloacal exstrophy. Prenatal ultrasonography provided the diagnosis of 14 of these defects with a changing sensitivity with the gestational age varying from 17% in the first trimester to 71.4% and 77.8% in the second and third trimesters, respectively. The relevance of this examination was improved when performed by an imaging specialist. The prenatal diagnosis of these defects indicated an amniocentesis in eight cases, allowing the diagnosis of two cases of trisomy 18. It also motivated a therapeutic termination of the pregnancy (TTP) in ten cases. Prenatal ultrasonography allowed better prenatal follow-up and planning of the delivery of the continued pregnancies. It indicated an emergency C-section in only one case by showing intestinal complications of gastroschisis. Four NNs died (two cases of omphalocele and two of gastroschisis), three of which postoperatively and the prenatal diagnosis did not improve survival. Prenatal ultrasonographic diagnosis provided a precise morphological study determining the type of the AAWD, a complete malformation assessment, and the prognosis factors. This resulted in adequate multidisciplinary pre and postnatal care, including a rigorous ultrasound follow-up, a TTP in case of associated defects, and emergency delivery once the complications of poor diagnosis are detected.

Epigenotype, genotype, and phenotype analysis of patients in Taiwan with Beckwith-Wiedemann syndrome

BACKGROUND

Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth disorder predisposing to tumorigenesis that results from abnormal expression or function of imprinted genes of chromosome 11p15.5.

METHODS

Forty-seven patients in Taiwan with clinical suspicion of BWS were referred for diagnostic testing based on methylation profiling of H19-associated imprinting center (IC) 1 and KCNQ1OT1-associated IC2 using high-resolution melting analysis, multiplex ligation-dependent probe amplification, or high-resolution quantitative methylation profiling.

RESULTS

Twenty-eight patients received a clinical diagnosis of BWS (the presence of 3 major features or 2 major features and at least 1 minor feature), 18 had suspected BWS (the presence of at least 1 major feature), and 1 had isolated Wilms' tumor. Nineteen patients were identified with IC2 hypomethylation (including 1 with isolated Wilms' tumor), 1 with IC1 hypermethylation, 2 with paternal uniparental disomy, and 1 with CDKN1C mutation. Several clinical features were found to be statistically different (P<0.05) between the 2 groups-clinical diagnosis of BWS (n=28) or suspected BWS (n=18)-including macroglossia, pre- or postnatal gigantism, abdominal wall defect, ear creases, facial nevus flammeus, BWS score, and the molecular diagnosis rate. Molecular lesion was detected in 81% of patients with the presence of three major features, compared with 33% and 28% of those with two or one major feature, respectively. The mean BWS score was 5.6 for 19 subjects with "IC2 hypomethylation", compared with 3.8 for 2 subjects with pUPD. The BWS score of one subject with CDKN1C mutation and one with IC1 hypermethylation was 6 and 7, respectively.

CONCLUSIONS

The BWS score was positively correlated with the molecular diagnosis rate (P<0.01). The BWS database of epigenotype, genotype, and phenotype is expected to promote better genetic counseling and medical care of these patients.

408 kb 15q11.2 microduplication by array comparative genomic hybridization in a fetus presenting with exomphalos, micrognathia, tetralogy of Fallot and normal karyotype: a genetic counseling dilemma in paternal carrier status

Exomphalos may be associated with chromosomal abnormalities and syndromes. Severe exomphalos (herniation of liver, midgut and spleen) associated with increased nuchal translucency was seen at first trimester screening test. Karyotype by chorionic villus sampling showed normal male fetus. Follow up scan at 16 and 18 weeks of gestation confirmed the severe exomphalos and detected micrognathia and tetralogy of Fallot. Array comparative genomic hybridization (a-CGH) further demonstrated a 408 kb 15q11.2 microduplication, with the father-to-be as healthy carrier. This is the first case of an association between 15q11.2 micorduplication and fetal sonographic anomalies. Genetic counseling for estimation of recurrent risk of congenital anomalies is discussed.

Fetal abdominal wall defects

The most common fetal abdominal wall defects are gastroschisis and omphalocele, both with a prevalence of about three in 10,000 births. Prenatal ultrasound has a high sensitivity for these abnormalities already at the time of the first-trimester nuchal scan. Major unrelated defects are associated with gastroschisis in about 10% of cases, whereas omphalocele is associated with chromosomal or genetic abnormalities in a much higher proportion of cases. Challenges in management of gastroschisis are related to the prevention of late intrauterine death, and the prediction and treatment of complex forms. With omphalocele, the main difficulty is the exclusion of associated conditions, not all diagnosed prenatally. An outline of the postnatal treatment of abdominal wall defects is given. Other rarer forms of abdominal wall defects are pentalogy of Cantrell, omphalocele, bladder exstrophy, imperforate anus, spina bifida complex, prune-belly syndrome, body stalk anomaly, and bladder and cloacal exstrophy; they deserve multidisciplinary counselling and management.

Genome-wide linkage and copy number variation analysis reveals 710 kb duplication on chromosome 1p31.3 responsible for autosomal dominant omphalocele

BACKGROUND

Omphalocele is a congenital birth defect characterised by the presence of internal organs located outside of the ventral abdominal wall. The purpose of this study was to identify the underlying genetic mechanisms of a large autosomal dominant Caucasian family with omphalocele.

METHODS AND FINDINGS

A genetic linkage study was conducted in a large family with an autosomal dominant transmission of an omphalocele using a genome-wide single nucleotide polymorphism (SNP) array. The analysis revealed significant evidence of linkage (non-parametric NPL = 6.93, p=0.0001; parametric logarithm of odds (LOD) = 2.70 under a fully penetrant dominant model) at chromosome band 1p31.3. Haplotype analysis narrowed the locus to a 2.74 Mb region between markers rs2886770 (63014807 bp) and rs1343981 (65757349 bp). Molecular characterisation of this interval using array comparative genomic hybridisation followed by quantitative microsphere hybridisation analysis revealed a 710 kb duplication located at 63.5-64.2 Mb. All affected individuals who had an omphalocele and shared the haplotype were positive for this duplicated region, while the duplication was absent from all normal individuals of this family. Multipoint linkage analysis using the duplication as a marker yielded a maximum LOD score of 3.2 at 1p31.3 under a dominant model. The 710 kb duplication at 1p31.3 band contains seven known genes including FOXD3, ALG6, ITGB3BP, KIAA1799, DLEU2L, PGM1, and the proximal portion of ROR1. Importantly, this duplication is absent from the database of genomic variants.

CONCLUSIONS

The present study suggests that development of an omphalocele in this family is controlled by overexpression of one or more genes in the duplicated region. To the authors' knowledge, this is the first reported association of an inherited omphalocele condition with a chromosomal rearrangement.

Síndrome de Beckwith-Wiedmann: relato de caso da intervenção fonoaudiológica

TEMA: descrever a evolução de um caso de Síndrome de Beckwith-Wiedmann com macroglossia submetido à fonoterapia quanto aos aspectos estruturais e miofuncionais do sistema estomatognático. PROCEDIMENTOS: inicialmente foram coletados os dados do prontuário e foi realizada a entrevista inicial com a mãe. Após, a paciente, com 1 ano e 2 meses de idade, foi submetida à avaliação fonoaudiológica clínica e foram realizados exames complementares (avaliação otorrinolaringológica, exame videofluoroscópico e avaliação audiológica). Após seis meses de terapia miofuncional com a utilização de técnicas passivas, foi realizada uma reavaliação. RESULTADOS: na avaliação fonoaudiológica inicial observou-se flacidez de lábios e bochechas; ausência de vedamento labial; língua com tensão diminuída, hemi-hipertrofia direita e acentuada projeção anterior; dificuldades na mastigação e na deglutição de alimentos sólidos. Decorridos seis meses de terapia miofuncional, constatou-se maior rigidez da musculatura de lábios e bochechas, posteriorização da língua com aumento da tensão muscular, e desempenho adequado na mastigação e deglutição de alimentos sólidos. CONCLUSÃO: a intervenção fonoaudiológica precoce, baseada em técnicas de terapia miofuncional, apresentou resultados considerados satisfatórios para este caso de Síndrome de Beckwith-Wiedmann com macroglossia.

CDKN1C mutations in HELLP/preeclamptic mothers of Beckwith-Wiedemann Syndrome (BWS) patients

Preeclampsia is the development of new-onset hypertension with proteinuria after 20 weeks of gestation. HELLP syndrome (haemolysis, elevated liver enzymes, and low platelet count) is a severe form of preeclampsia with high rates of neonatal and maternal morbidity. In recent years, loss of function of cdkn1c (a tight-binding inhibitor of G1 cyclin/cyclin-dependent kinase complexes and a negative regulator of cell proliferation) has been observed in several mouse models of preeclampsia. In this paper, we report on three women with HELLP/preeclampsia who had children with Beckwith Wiedemann syndrome, a complex genetic disorder characterised, among other findings, by overgrowth, omphalocele and macroglossia. All three children displayed mutations in CDKN1C predicted to generate truncated proteins. Two of the mutations were maternally inherited while the third was de novo. This finding suggests a fetal contribution to the maternal disease. To the best of our knowledge this is the first report of CDKN1C mutations in children born to women with preeclampsia/HELLP syndrome, thus suggesting the involvement of an imprinted gene in the pathophysiology of preeclampsia.

Immunohistochemical expression of p57 in placental vascular proliferative disorders of preterm and term placentas

P57 protein is implicated in some human imprinting disorders such as hydatiform mole and Beckwith-Wiedemann syndrome (BWS), both characterized by mesenchymal and vascular placental abnormalities. We investigated p57 immunohistochemical expression in placental vascular proliferative disorders of preterm and term placentas, including chorangiosis (n = 5), chorangiomatosis (n = 2), chorangiomas (n = 7), umbilical cord angioma (n = 1), and placental mesenchymal dysplasia (PMD) (n = 7). P57 was expressed in decidua, cytotrophoblast, intermediate trophoblast and stromal cells of normal terminal, intermediate and stem villi, umbilical cord, chorangiosis, chorangiomatosis, and chorangiomas. In contrast, there was a loss of p57 expression in stromal cells of dysplastic stem villi in all cases of PMD regardless of whether associated with BWS or not. P57 seems to be involved in the pathogenesis of a subset of placental vascular proliferative disorders in preterm and term placentas, such as PMD. The loss of p57 expression in PMD could be of diagnostic value in helping to distinguish this rare placental lesion from its mimickers.