Fryns syndrome with Hirschsprung disease: Support for possible neural crest involvement

Congenital diaphragmatic hernia in 22q11.2 deletion syndrome

We report the important association of congenital diaphragmatic hernia (CDH) and 22q11.2 deletion syndrome (22q11.2DS). The prevalence of CDH in our cohort of patients with 22q11.2DS is 0.8% (10/1246), which is greater than in the general population (0.025%). This observation suggests that 22q11.2DS should be considered when a child or fetus presents with CDH, in particular when other clinical findings associated with the 22q11.2DS are present, such as congenital cardiac defects. Furthermore, this finding may lead to the identification of an additional locus for diaphragmatic hernia in the general population. © 2016 Wiley Periodicals, Inc.

Architectural malformation of the muscularis propria as a cause for intestinal pseudo-obstruction: two cases and a review of the literature

Two patients are presented with intestinal pseudo-obstruction and malformations of their intestinal muscularis propria. Histopathological findings in each case indicate a distinct alteration of intestinal muscle architecture. The 1st patient, a teenager with lifelong constipation, had an additional circular muscle tunic in 2 dilated segments of his large intestine. The 2nd patient, an infant with multiple malformations, had diffuse abnormal layering of his small intestine. The rare reports of other individuals with similar pathological findings are discussed.

Syndrome de Fryns. Présentation de 3 nouvelles observations

BACKGROUND

Fryns syndrome is a lethal autosomal recessive syndrome which includes congenital diaphragmatic hernia (CDH), pulmonary hypoplasia, cranio-facial manifestations including a coarse face, a cleft palate / lip and cloudy corneae, distal limb hypoplasia and internal malformations including central nervous system, cardiovascular, gastrointestinal, urogenital and skeletal anomalies.

CASES REPORT

We report on 3 patients with Fryns syndrome in the french Indian Ocean islands (La Réunion and Mayotte islands). Pregnancies were complicated by polyhydramnios. All patients had coarse face, cloudy corneae, cleft lip / palate or high-arched palate, hypoplastic nails and brachytelephalangy. They died in the neonatal period. Two had CDH and 1 did not have a diaphragmatic involvement but a severe respiratory distress syndrome with refractory hypoxemia. Cytogenetic studies of blood lymphocytes and skin fibroblasts were normal.

CONCLUSIONS

Fryns syndrome is the most common multiple congenital anomaly associated with CDH. The diagnosis is strongly suggested when CHD and brachytelephalangy are associated. Phenotypes with CDH similar to Fryns syndrome have been described with cytogenetic aberrations with G-banded chromosome analysis and submicroscopic chromosome deletions detected by high resolution karyotyping or array comparative genomic hybridization (CGH). Exclusion of chromosome aberrations (including isochromosome 12p in skin fibroblasts) is needed prior to making the diagnosis of Fryns syndrome. In sporadic cases, high resolution karyotyping or array CGH should be performed for correct diagnosis and genetic counselling.

Stephen L. Gans Distinguished Overseas Lecture. The neural crest in pediatric surgery

AIM

This review highlights the relevance of the neural crest (NC) as a developmental control mechanism involved in several pediatric surgical conditions and the investigative interest of following some of its known signaling pathways.

METHODS

The participation of the NC in facial clefts, ear defects, branchial fistulae and cysts, heart outflow tract and aortic arch anomalies, pigmentary disorders, abnormal enteric innervation, neural tumors, hemangiomas, and vascular anomalies is briefly reviewed. Then, the literature on clinical and experimental esophageal atresia-tracheoesophageal fistula (EA-TEF) and congenital diaphragmatic hernia (CDH) is reviewed for the presence of associated NC defects. Finally, some of the molecular signaling pathways involved in both conditions (sonic hedgehog, Hox genes, and retinoids) are summarized.

RESULTS

The association of facial, cardiovascular, thymic, parathyroid, and C-cell defects together with anomalies of extrinsic and intrinsic esophageal innervation in babies and/or animals with both EA-TEF and CDH strongly supports the hypothesis that NC is involved in the pathogenesis of these malformative clusters. On the other hand, both EA-TEF and CDH are observed in mice mutant for genes involved in the previously mentioned signaling pathways.

CONCLUSIONS

The investigation of NC-related molecular pathogenic pathways involved in malformative associations like EA-TEF and CDH that are induced by chromosomal anomalies, chemical teratogens, and engineered mutations is a promising way of clarifying why and how some pediatric surgical conditions occur. Pediatric surgeons should be actively involved in these investigations.

Cardiovascular malformations in Fryns syndrome: is there a pathogenic role for neural crest cells?

We performed a comprehensive literature and case report review to characterize the cardiovascular malformations (CVMs) associated with Fryns syndrome (OMIM #229850), a multiple congenital anomaly/mental retardation syndrome consisting of diaphragmatic defects, significant pulmonary hypoplasia, distinctive facial appearance, distal digital hypoplasia, and numerous other external and internal anomalies. A total of 112 patients meeting diagnostic guidelines for Fryns syndrome were identified, of whom 82 met narrowly defined criteria (Group I) and 30 met broader diagnostic criteria (Group II). Twelve patients reported as having Fryns syndrome with atypical features (Group III) were also analyzed. A CVM was reported in 51% (42 of 82) of Group I patients, most commonly an atrial or ventricular septal defect (VSD) (23 of 42, 55%). Conotruncal and aortic arch CVMs were common (11 of 42, 26%), but not significantly so compared to the general population of infants to age 1 year [Ferencz et al., 1997]. Recognizing that minor septal defects associated with congenital diaphragmatic hernia (CDH) may occur in response to altered hemodynamics (instead of being a bonafide CVM), we excluded four patients reported as having hemodynamically insignificant VSDs. Following these exclusions, conotruncal CVMs were found more commonly than in the general population (11 of 38, 29%, P < or = 0.025). In Group II, 9 of 30 (30%) had a CVM with no predominant type among the small number of cases reviewed. Among the atypical Fryns syndrome patients in Group III, half (6 of 12, 50%) had a CVM; most (4 of 6, 67%) were conotruncal, in particular, type B interrupted aortic arch (3 of 4). Patients with Fryns syndrome have a high rate of CVMs, warranting thorough cardiac evaluation including echocardiogram (fetal and/or postnatal) in all patients, similar to the evaluation for other patients with diaphragmatic hernia. The possible association between conotruncal CVMs and Fryns syndrome may provide additional support for an etiologic role of genes related to neural crest cell development in the pathogenesis of Fryns syndrome and hence, congenital diaphragmatic hernia.

The contribution of associated congenital anomalies in understanding Hirschsprung's disease

Hirschsprung's disease (HSCR) is a complex congenital disorder which, from a molecular perspective, appears to result due to disruption of normal signalling during development of enteric nerve cells, resulting in aganglionosis of the distal bowel. Associated congenital anomalies occur in at least 5-32% (mean 21%) of patients and certain syndromic phenotypes have been linked to distinct genetic sites, indicating underlying genetic associations of the disease and probable gene-gene interaction in its pathogenesis. Clear-cut associations with HSCR include Down's syndrome, dominant sensorineural deafness, Waardenburg syndrome, neurofibromatosis, neuroblastoma, phaeochromocytoma, the MEN type IIB syndrome and other abnormalities. Individual anomalies vary from 2.97% to 8%, the most frequent being the gastrointestinal tract (GIT) (8.05%), the central nervous system (CNS) and sensorineural anomalies (6.79%) and the genito-urinary tract (6.05%). Other associated systems include the musculoskeletal (5.12%), cardiovascular systems (4.99%), craniofacial and eye abnormalities (3%) and less frequently the skin and integumentary system (ectodermal dysplasia) and syndromes related to cholesterol and fat metabolism. In addition to associations with neuroblastoma and tumours related to MEN2B, HSCR may also be associated with tumours of neural origin such as ganglioneuroma, ganglioneuroblastoma, retinoblastoma and tumours associated with neurofibromatosis and other autonomic nervous system disturbances. The contribution of the major susceptibility genes on chromosome 10 (RET) and chromosome 13 (EDNRB) is well established in the phenotypic expression of HSCR. Whereas major RET mutations may result in HSCR by haploinsufficiency in 20-25% of cases, the etiology of the majority of sporadic HSCR is not as clear, appearing to arise from the combined cumulative effects of susceptibility loci at critical genes controlling the mechanisms of cell proliferation, differentiation and maturation. In addition, potential "modifying" associations exist with chromosome 2, 9, 20, 21 and 22, and we explore the importance of certain flanking genes of critical areas in the final phenotypic expression of HSCR.