Recurrent congenital diaphragmatic hernia in Ehlers-Danlos syndrome

Underlying genetic etiologies of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is often detectable prenatally. Advances in genetic testing have made it possible to obtain a molecular diagnosis in many fetuses with CDH. Here, we review the aneuploidies, copy number variants (CNVs), and single genes that have been clearly associated with CDH. We suggest that array-based CNV analysis, with or without a chromosome analysis, is the optimal test for identifying chromosomal abnormalities and CNVs in fetuses with CDH. To identify causative sequence variants, whole exome sequencing (WES) is the most comprehensive strategy currently available. Whole genome sequencing (WGS) with CNV analysis has the potential to become the most efficient and effective means of identifying an underlying diagnosis but is not yet routinely available for prenatal diagnosis. We describe how to overcome and address the diagnostic and clinical uncertainty that may remain after genetic testing, and review how a molecular diagnosis may impact recurrence risk estimations, mortality rates, and the availability and outcomes of fetal therapy. We conclude that after the prenatal detection of CDH, patients should be counseled about the possible genetic causes of the CDH, and the genetic testing modalities available to them, in accordance with generally accepted guidelines for pretest counseling in the prenatal setting.

Respiratory manifestations in the Ehlers-Danlos syndromes

Persons with the Ehlers-Danlos syndromes (EDS) report a wide range of respiratory symptoms, most commonly shortness of breath, exercise limitation, and cough. Also reported are noisy breathing attributed to asthma, difficulty with deep inhalation, and inspiratory thoracic pain. The literature consists of case reports and small cross-sectional and cohort studies. One case-control study estimated twofold to threefold greater respiratory disease burden among persons with EDS as compared to controls. The differential diagnosis for symptoms is broad. Structural alterations include pectus deformities, scoliosis, recurrent rib subluxations, and tracheobronchomalacia, associated with varying degrees of physiologic impairment. Those with vascular EDS have an increased risk of pneumothorax, intrapulmonary bleeding, cysts, and nonmalignant fibrous nodules. Functional aerodigestive manifestations such as inducible laryngeal obstruction may be misdiagnosed as asthma, with gastro-esophageal dysmotility and reflux as common contributing factors. Inflammatory manifestations include costochondritis, bronchiectasis, and localized respiratory allergic and nonallergic mast cell activation. Cranio-cervical instability can dysregulate respiratory control pathways. There is a need for careful phenotyping using standardized clinical tools and patient-reported outcomes and continuing collaboration with aerodigestive specialists including otolaryngologists and gastroenterologists. Also needed is further evaluation of respiratory symptoms in persons with hypermobility spectrum disorders. Personalized monitoring strategies are invaluable for interpretation and long-term management of respiratory symptoms.

Pulmonary Manifestations of Skin Disorders in Children

Systemic diseases often manifest with cutaneous findings. Many pediatric conditions with prominent skin findings also have significant pulmonary manifestations. These conditions include both inherited multisystem genetic disorders such as yellow-nail syndrome, neurofibromatosis type 1, tuberous sclerosis complex, hereditary hemorrhagic telangiectasia, Klippel-Trénaunay-Weber syndrome, cutis laxa, Ehlers-Danlos syndrome, dyskeratosis congenita, reactive processes such as mastocytosis, and aquagenic wrinkling of the palms. This overview discusses the pulmonary manifestations of skin disorders.

Natural history of gastrointestinal manifestations in vascular Ehlers-Danlos syndrome: A 17-year retrospective review

BACKGROUND AND AIM

Vascular Ehlers-Danlos syndrome (vEDS) is a rare connective tissue disorder due to heterozygous mutations in the COL3A1 gene with a dominant negative effect. Spontaneous bowel perforation and intra-abdominal organ rupture are common complications of vEDS. Other gastrointestinal (GI) manifestations may occur but have not been extensively characterized. We herein describe the natural history of GI events and surgery-related complications in patients with vEDS.

METHODS

A retrospective review of GI events in a large cohort of molecularly proven vEDS patients was conducted, after exclusion of mild forms of the disease.

RESULTS

Of 133 patients, 41% had a history of GI manifestations with 112 events, mean 2.0 ± 1.3 events per patient. There was an earlier occurrence of GI events in men (P 0.008). Cumulative incidence was 58% for all patients, higher in men and in patients with splice-site variants. Recurrence of GI events was reported in more than 50% of patients. Colonic perforation was the first digestive event for 47% of patients. Of 85 GI surgeries, 37 (43%) were complicated with 43 events. Nine deaths were reported in this population.

CONCLUSIONS

Vascular Ehlers-Danlos syndrome is characterized not only by bowel perforation but also by a wide variety of GI complications that occur in close to half (41%) of patients. The pattern of GI fragility seems more severe in males and splice-site variants. Complications of GI surgery are common and are related with tissue fragility/friability.

Congenital diaphragmatic hernias: from genes to mechanisms to therapies

Congenital diaphragmatic hernias (CDHs) and structural anomalies of the diaphragm are a common class of congenital birth defects that are associated with significant morbidity and mortality due to associated pulmonary hypoplasia, pulmonary hypertension and heart failure. In ∼30% of CDH patients, genomic analyses have identified a range of genetic defects, including chromosomal anomalies, copy number variants and sequence variants. The affected genes identified in CDH patients include transcription factors, such as GATA4, ZFPM2, NR2F2 and WT1, and signaling pathway components, including members of the retinoic acid pathway. Mutations in these genes affect diaphragm development and can have pleiotropic effects on pulmonary and cardiac development. New therapies, including fetal endoscopic tracheal occlusion and prenatal transplacental fetal treatments, aim to normalize lung development and pulmonary vascular tone to prevent and treat lung hypoplasia and pulmonary hypertension, respectively. Studies of the association between particular genetic mutations and clinical outcomes should allow us to better understand the origin of this birth defect and to improve our ability to predict and identify patients most likely to benefit from specialized treatment strategies.

Measurement of hydroxyproline and nitric oxide, and comparison of sac fluid acidity in different inguinal pathologies

PURPOSE

To compare hydroxyproline and nitric oxide levels, and fluid acidity between sac tissues from inguinal hernia, hydrocele and undescended testis patients.

MATERIAL AND METHOD

Thirty patients were in the inguinal hernia group, 11 patients in the hydrocele group and 5 patients in the undescended testis with inguinal hernia group. Intrasaccular fluid acidity, and nitric oxide and hydroxyproline levels in sac tissues were measured and analyzed statistically between groups.

RESULTS

Intrasaccular fluid could be obtained from 24 inguinal hernia and 6 hydrocele patients. Acidity level (pH) was 7.5 ± 0.74 in the hernia group and 7.86 ± 0.63 in the hydrocele group (p < 0.05). All patients in the three groups were evaluated for nitric oxide and hydroxyproline. Results for hydroxyproline (mg/g dry tissue)/nitric oxide (nmol/g wet tissue) were 3.53 ± 0.54/2.02 ± 0.39 for inguinal hernia, 2.89 ± 0.9/1.92 ± 1.05 for hydrocele and 3.02 ± 1.23/2.86 ± 1.09 for undescended testis group (p > 0.05).

CONCLUSION

Hydroxyproline and nitric oxide pathways do not seem to be responsible for the different characteristics of inguinal diseases. However, differences in the acidity of sac fluid may be evidence of the different mechanisms of hernia and hydrocele formation.

Criteria for definition of a complex abdominal wall hernia

PURPOSE

A clear definition of "complex (abdominal wall) hernia" is missing, though the term is often used. Practically all "complex hernia" literature is retrospective and lacks proper description of the population. There is need for clarification and classification to improve patient care and allow comparison of different surgical approaches. The aim of this study was to reach consensus on criteria used to define a patient with "complex" hernia.

METHODS

Three consensus meetings were convened by surgeons with expertise in complex abdominal wall hernias, aimed at laying down criteria that can be used to define "complex hernia" patients, and to divide patients in severity classes. To aid discussion, literature review was performed to identify hernia classification systems, and to find evidence for patient and hernia variables that influence treatment and/or prognosis.

RESULTS

Consensus was reached on 22 patient and hernia variables for "complex" hernia criteria inclusion which were grouped under four categories: "Size and location", "Contamination/soft tissue condition", "Patient history/risk factors", and "Clinical scenario". These variables were further divided in three patient severity classes ('Minor', 'Moderate', and 'Major') to provide guidance for peri-operative planning and measures, the risk of a complicated post-operative course, and the extent of financial costs associated with treatment of these hernia patients.

CONCLUSION

Common criteria that can be used in defining and describing "complex" (abdominal wall) hernia patients have been identified and divided under four categories and three severity classes. Next step would be to create and validate treatment algorithms to guide the choice of surgical technique including mesh type for the various complex hernias.

Development of the diaphragm -- a skeletal muscle essential for mammalian respiration

The mammalian diaphragm muscle is essential for respiration, and thus is one of the most critical skeletal muscles in the human body. Defects in diaphragm development leading to congenital diaphragmatic hernias (CDH) are common birth defects and result in severe morbidity or mortality. Given its functional importance and the frequency of congenital defects, an understanding of diaphragm development, both normally and during herniation, is important. We review current knowledge of the embryological origins of the diaphragm, diaphragm development and morphogenesis, as well as the genetic and developmental aetiology of diaphragm birth defects.

Osteogenesis imperfecta and congenital diaphragmatic hernia

Osteogenesis imperfecta and congenital diaphragmatic hernia are both conditions that can occur due to genetic mutation. We present the first case to be reported of a child with both osteogenesis imperfecta and congenital diaphragmatic hernias, showing that the incidence of this presentation may be more than chance.

Massive spontaneous diaphragmatic rupture in Ehlers-Danlos syndrome

Ehlers-Danlos syndrome (EDS) is a rare disorder caused by abnormalities in the synthesis and structure of collagen. The resultant tissue fragility and weakness can lead to multiple surgical conditions. In this report we present the very rare and life threatening case of a massive spontaneous diaphragmatic rupture in a 35-year-old man with EDS and reflect on the literature, highlighting points to consider when managing such complex patients.

Vitamin A deficiency (VAD), teratogenic, and surgical models of congenital diaphragmatic hernia (CDH)

Congenital diaphragmatic hernia (CDH) is a congenital malformation that occurs with a frequency of 0.08 to 0.45 per 1,000 births. Children with CDH are born with the abdominal contents herniated through the diaphragm and exhibit an associated pulmonary hypoplasia which is frequently accompanied by severe morbidity and mortality. Although the etiology of CDH is largely unknown, considerable progress has been made in understanding its molecular mechanisms through the usage of genetic, teratogenic, and surgical models. The following review focuses on the teratogenic and surgical models of CDH and the possible molecular mechanisms of nitrofen (a diphenyl ether, formerly used as an herbicide) in both induction of CDH and pulmonary hypoplasia. In addition, the mechanisms of other compounds including several anti-inflammatory agents that have been linked to CDH will be discussed. Furthermore, this review will also explore the importance of vitamin A in lung and diaphragm development and the possible mechanisms of teratogen interference in vitamin A homeostasis. Continued exploration of these models will bring forth a clearer understanding of CDH and its molecular underpinnings, which will ultimately facilitate development of therapeutic strategies.

Molecular genetics of congenital diaphragmatic defects

Congenital diaphragmatic hernia (CDH) is a severe birth defect that is accompanied by malformations of the lung, heart, testis, and other organs. Patients with CDH may have any combination of these extradiaphragmatic defects, suggesting that CDH is often a manifestation of a global embryopathy. This review highlights recent advances in human and mouse genetics that have led to the identification of genes involved in CDH. These include genes for transcription factors, molecules involved in cell migration, and extracellular matrix components. The expression patterns of these genes in the developing embryo suggest that mesenchymal cell function is compromised in the diaphragm and other affected organs in patients with CDH. We discuss potential mechanisms underlying the seemingly random combination of diaphragmatic, pulmonary, cardiovascular, and gonadal defects in these patients.