Prenatal diagnosis of caudal regression with heterotaxy syndrome: "A mermaid with a broken heart".

Caudal regression syndrome (CRS) is a rare congenital malformation with varying degrees of early gestational developmental failure. It is characterized by agenesis of the sacrum and lumbar spine, with lower limb neurological deficit and accompanying deformities of the pelvis, lower extremities, genitourinary, and gastrointestinal systems. We report a case of CRS associated with rare complex congenital heart defect, that is, heterotaxy syndrome, diagnosed prenatally.

The developmental biology of genetic Notch disorders.

Notch signaling regulates a vast array of crucial developmental processes. It is therefore not surprising that mutations in genes encoding Notch receptors or ligands lead to a variety of congenital disorders in humans. For example, loss of function of Notch results in Adams-Oliver syndrome, Alagille syndrome, spondylocostal dysostosis and congenital heart disorders, while Notch gain of function results in Hajdu-Cheney syndrome, serpentine fibula polycystic kidney syndrome, infantile myofibromatosis and lateral meningocele syndrome. Furthermore, structure-abrogating mutations in NOTCH3 result in CADASIL. Here, we discuss these human congenital disorders in the context of known roles for Notch signaling during development. Drawing on recent analyses by the exome aggregation consortium (EXAC) and on recent studies of Notch signaling in model organisms, we further highlight additional Notch receptors or ligands that are likely to be involved in human genetic diseases.

Orally administered melatonin prevents lipopolysaccharide-induced neural tube defects in mice.

Lipopolysaccharide (LPS) has been associated with adverse pregnant outcomes, including fetal demise, intra-uterine growth restriction (IUGR), neural tube defects (NTDs) and preterm delivery in rodent animals. Previous studies demonstrated that melatonin protected against LPS-induced fetal demise, IUGR and preterm delivery. The aim of the present study was to investigate the effects of melatonin on LPS-induced NTDs. All pregnant mice except controls were intraperitoneally injected with LPS (25 µg/kg) daily from gestational day (GD)8 to GD12. Some pregnant mice were orally administered with melatonin (MT, 50 mg/kg) before each LPS injection. A five-day LPS injection resulted in 27.5% of fetuses with anencephaly, exencephaly or encephalomeningocele. Additional experiment showed that maternal LPS exposure significantly down-regulated placental proton-coupled folate transporter (pcft) and disturbed folate transport from maternal circulation through the placentas into the fetus. Interestingly, melatonin significantly attenuated LPS-induced down-regulation of placental pcft. Moreover, melatonin markedly improved the transport of folate from maternal circulation through the placentas into the fetus. Correspondingly, orally administered melatonin reduced the incidence of LPS-induced anencephaly, exencephaly or encephalomeningocele. Taken together, these results suggest that orally administered melatonin prevents LPS-induced NTDs through alleviating LPS-induced disturbance of folate transport from maternal circulation through the placenta into the fetus.

Traffic jam in the primitive streak: the role of defective mesoderm migration in birth defects.

Gastrulation is the process in which the three germ layers are formed that contribute to the formation of all major tissues in the developing embryo. We here review mouse genetic models in which defective gastrulation leads to mesoderm insufficiencies in the embryo. Depending on severity of the abnormalities, the outcomes range from incompatible with embryonic survival to structural birth defects, such as heart defects, spina bifida, or caudal dysgenesis. The combined evidence from the mutant models supports the notion that these congenital anomalies can originate from perturbations of mesoderm specification, epithelial-mesenchymal transition, and mesodermal cell migration. Knowledge about the molecular pathways involved may help to improve strategies for the prevention of major structural birth defects.

Encephalocystocele - uncommon diagnosis in prenatal medicine.

Encephalocystocele is a developmental malformation characterized by brain herniation accompanied with extracranial cystic protrusion of the ventricular system. This nosological unit is often overlooked and insufficiently classified merely as encephalocele. Herein, two exceptionally clear cases of the parieto-occipital cranioschisis with encephalocystocele and congenital hydrocephalus of the lateral ventricles are documented with 2-dimensional/3-dimensional sonographic images and the corresponding MRI findings. In both cases, prenatal diagnosis was confirmed by autopsy.

[Cervical meningocele with filiform connection. Case report]. / Meningocele cervical con conexión filiforme. Reporte de un caso.

The meningocele is the least common form of spina bifida cystica and represents less than 10% of cases of this disorder. A case of a female patient aged 26 with a history of two pregnancies and two previous cesarean sections, present pregnancy unplanned, uncontrolled during the first trimester prenatal and without supplementation with folic acid. Family history of consanguinity with her husband (second cousins) and psychomotor reassessed in four maternal cousins. The first follow-up visit the patient was at 34 weeks of pregnancy. The ultrasonographic findings were: cervical meningocele posterior filiform connection between the first and second cervical vertebrae, lateral ventriculomegaly and third and fourth ventricles and hydrocephalus secondary. Cesarean section was performed at 37 weeks gestation and was a newborn male 3.000 g, 52 cm, head circumference of 36 cm, Apgar 8/9, Capurro 37 weeks of gestation. In the posterior cervical region tumor was located a soft 5 x 5 cm with intact skin, adhered to deep planes. Movement of all four extremities without neurological involvement. He referred to the department of neurosurgery for shunt placement and subsequently performed surgical excision of the meningocele.

Meningocele following aplasia of the occipital bone.

We describe a first trimester female foetus with aplasia of the occipital bone allowing a meningocele without skin coverage to be formed. The pregnancy was terminated, and on later autopsy the brain appeared to be intact. The foetus carried an apparently balanced translocation 46,XX,t(3;9)(p21.3;q22.3) inherited from a normal father and grandfather.

[Progress in the prenatal treatment and anesthetic considerations for fetal surgery].

Recent advances in prenatal diagnosis have made fetal surgery as a possible treatment for a wide variety of fetal diseases. Fetal surgeries consist of minimally invasive fetal surgery such as ultrasound guided procedure and fetoscopic surgery, open fetal surgery, and ex-utero intrapartum treatment. Effectiveness of these fetal surgeries has been discussed and proved to be effective for some diseases. If a fetal surgery is planned, an anesthesiologist is required to offer optimal anesthesia both for mother and fetus. For this purpose, anesthesiologists are supposed to know outlines of the fetal treatment in addition to pediatric and obstetric anesthesia, as a member of multidisciplinary team. In this review, outlines of fetal treatment will be introduced and anesthetic considerations for fetal surgeries will be discussed.

Prenatal screening and diagnosis of neural tube defects.

This review article discusses prenatal screening and diagnosis of neural tube defects (NTD). High detection rates occur in countries operating ultrasound screening programmes because classical two-dimensional ultrasound cranial signs (lemon shaped head, banana cerebellum, ventriculomegaly) are important diagnostic clues to the presence of spina bifida. Careful evaluation of both the spine and a search for other abnormalities is warranted. Important prognostic information for spina bifida relates to the lesion level, with a "watershed" between L3 and L4 marking a very high chance of being wheelchair bound with the higher lesions. Three-dimensional ultrasound using multiplanar views can achieve diagnostic accuracy within one vertebral body in around 80% of patients. There are high rates of pregnancy termination for spina bifida in many European countries, but the use of new imagining techniques allow better prediction of outcome, and consequently a refinement of prenatal counselling.

[Tumoral degeneration occurring over a non-healing meningocele. Report of two cases]. / Degeneración tumoral en meningocele no intervenido. Descripción de dos casos.

A giant meningocelic sac has not been usually described in adult patients, due to the fact that it shows a low incidence and few newborn have survived to date though the malformation is benign. We report two cases of patients born with the described malformation and who were not operated at that time, so they reached adulthood with bigger sacs. They needed surgery to remove the sacs, for a different reason. The older one had a fistulous abcess but the LCR did not come out, and it did not improved by the application of topic and antibiotic treatment. The other patient showed a progressive growth of the malformation during the last year, skin hardening and pain. The histological study of the dried sacs proved the existence of a carcinomatous degeneration. In the patients we have treated, it seems that a chronic irritation of the LCR and the appearance of multipotent cells in the meningocele may favour the malignancy of the tissues surrounding the sac. This possible malignancy, already described in the bibliography, suggests a prompt elective surgical treatment of the patients with these congenital lesions as soon as possible.

Neurocutaneous melanosis associated with Dandy-Walker malformation and a meningohydroencephalocele. Case report.

Neurocutaneous melanosis and Dandy-Walker malformation are both forms of rare congenital neurodysplasia. Interestingly, 8 to 10% of patients with neurocutaneous melanosis also harbor an associated Dandy-Walker malformation, indicating that these developmental abnormalities share a common origin. The authors describe a case of neurocutaneous melanosis associated with Dandy-Walker malformation and an occipital meningohydroencephalocele with a giant melanotic nevus. Multiple congenital liver masses were also observed in the infant. The occipital nevus was totally excised, and ventriculoperitoneal and cyst-peritoneal shunts were created to prevent subsequent hydrocephalus. Findings in this case support the possibility that excessive melanocytes hinder normal mesenchymal development, causing Dandy-Walker malformation and an occipital meningocele.

Cephaloceles and abnormal venous drainage.

Seven cases of parietal cephalocele and three cases of occipital cephalocele associated with abnormal venous drainage were evaluated, and the mechanism of the development for venous system was discussed from the embryological viewpoint. In parietal cephaloceles the abnormally draining vein, which corresponds to the straight sinus, ascended along the interhemisphere apart from the tentorium and emptied into the superior sagittal sinus below the cephalocele. The superior sagittal sinus formed the confluence, which was positioned high up. Intraoperative findings revealed that cephalocele penetrated the superior sagittal sinus at the midline. In the case of occipital cephalocele, the straight sinus followed a postero-superior course, to drain into the confluence just above the neck of cephalocele. The results of our study suggest that the causation of abnormal venous drainage in the great vein of Galen, the straight sinus and the superior sagittal sinus may be secondary, through interaction with a developmentally pre-existing cephalocele.

A novel embryogenetic mechanism for Currarino's triad: inadequate dorsoventral separation of the caudal eminence from hindgut endoderm.

Currarino's triad is a congenital malformation involving the combination of anorectal stenosis, a presacral mass (most often a teratoma or ventral menigocele) and an anterior sacral bony defect (scimitar sacrum). Current theories regarding its embryogenesis are difficult to reconcile with our current understanding of caudal neuraxial and hindgut development. Caudal neuraxial structures develop from the caudal eminence (or tail bud), which normally separates from the hindgut endoderm concurrent with ingrowth of the posterior notochord during late gastrulation. We describe the first reported association of Currarino's triad with a caudal split cord malformation. It has previously been proposed that split cord malformations and related 'complex dysraphic malformations' involving abnormalities of one or more of the three primary germ layers arise through disordered midline axial integration during gastrulation. The presence of a split cord malformation in a patient with Currarino's triad suggests that the two disorders share a common embryogenetic pathway. We propose that the malformations of Currarino's triad arise through a failure of dorsoventral separation of the caudal eminence from the hindgut endoderm during late gastrulation.

Multisite neural tube closure in humans.

We present evidence for multisite NT closure in humans with representative examples of types of NTDs that would be expected if NT closure in humans is similar to experimental mice models. We determine that the majority of NTDs can be classified by the multisite closure model. Further evidence for multisite closure of the NT is apparent in previous epidemiological studies, recognized monogenic disorders, and environmental and teratogenic exposures. Previous reliance on the single-site closure model has resulted in grouping of anomalies, obscuring evidence for multisite NT closure, etiological heterogeneity, varying recurrence risks, and site-specific effects of environmental factors. The NTDs have been previously referred to as being multifactorial, due to multiple genes and environmental factors. Etiological heterogeneity has been demonstrated previously as well. Classification of NTDs by closure site will be beneficial in better defining etiologies and environmental susceptibilities. Similarly, it is apparent to us that genetic variations in closure sequence, rate, and location are most likely monogenic and result in affected embryos being more susceptible to specific environmental factors, such as the effect of folic acid deficiency. Individual closure sites are most likely under the control of specific embryonically expressed genes, whose monogenic nature may not be apparent postnatally. For the disorders such as Meckel-Gruber syndrome and Walker-Warburg syndrome, the monogenic etiology for NTDs in affected individuals is apparent because of associated malformations. There are three important implications of this study: The first is that monogenic mouse models will be helpful in investigating the pathogenesis of NTDs in humans. The homologies between the mouse and human genome may allow linkage studies to be done in some families who have recurrence of NTDs. Second, in order to have useful results from studies of NTDs, NT anomalies need to be accurately described, either by the classical nomenclature (eg, meroacranium) or by referring to the corresponding closure site involvement (eg, closure 2 defect). Special attention needs to be addressed to those NTDs that do not appear to fit into a discrete closure site (eg, midthoracic spina bifida cystica) or laterally displaced NTDs, since they may be due to other etiologies. With improved nutrition, particularly folic acid treatment, specific etiologies for the remaining NTDs may become more apparent. Finally, recurrence risks for NTDs may vary between families based on the closure site affected, and whether or not associated anomalies are present.

Cerebellar dermoid tumor and occipital meningocele in a monozygotic twin: clues to the embryogenesis of craniospinal dysraphism.

A case of monochorionic/monoamnionic twin with discordant occipital developmental malformations is presented. One female twin appeared to have an occipital meningocele with cerebellar aplasia and died immediately after birth. The other twin presented with signs and symptoms of raised intracranial pressure at the age of 7 months. Severe hydrocephalus was present due to an infected intracerebellar dermoid tumor with a contiguous occipital dermal sinus. The clinical and pathological characteristics are described and the different theories concerning twinning, embryogenesis, and dysmorphology in relation to neural tube defects are discussed. Analysis of the features of these monozygotic twins indicates that a meningocele is not a post-neurulation disorder but results from deficient neurulation, probably due to mesodermal insufficiency.

Cervical meningoceles and myelocystoceles: a unifying hypothesis.

The classification and embryogenesis of cystic cervical dysraphic lesions are discussed in the light of the authors' experience and review of the literature. It is felt that these lesions are best described as meningoceles or myelocystoceles, and the use of the term 'myelomeningocele' may be more confusing than clarifying. The authors hypothesize that the cervical meningocele and the myelocystocele are part of a spectrum of the same underlying developmental abnormality, namely limited dorsal myeloschisis, with the eventual abnormality depending on the presence or absence of associated hydromyelia.

Syndromes identified in fetuses with prenatally diagnosed cephaloceles.

An evaluation of all fetuses from our institution with prenatally diagnosed cephaloceles was conducted to determine the frequency and spectrum of genetic syndromes associated with this abnormality. Review of the sonographic images, postnatal autopsy or pathology reports, delivery room records, paediatric neurosurgical findings, radiographs, and cytogenetic data were collected. Fifteen postnatally confirmed cases of prenatally diagnosed cephaloceles and two misdiagnosed cases were identified. Thirteen were midline occipital lesions, one was frontoparietal, and one was frontoethmoidal. Excluding microcephaly, hydrocephaly, and distortion of intracranial anatomy, 9 of 15 (60 per cent) had other associated anomalies, including two fetuses with aneuploidy. The prenatal diagnosis of a cephalocele should initiate a thorough search for other abnormalities. In this series, there were three multifactorial, two chromosomal, two sporadic, and two autosomal recessive syndromes identified. An accurate diagnosis is critical in determining the prognosis and providing appropriate genetic counselling.

Evidence for multi-site closure of the neural tube in humans.

Four separate initiation sites for neural tube (NT) fusion have been demonstrated recently in mice and other experimental animals. We evaluated the question of whether the multisite model vs. the traditional single-site model of NT closure provided the best explanation for neural tube defects (NTDs) in humans. Evidence for segmental vs. continuous NT closure was obtained by review of our recent clinical cases of NTDs and previous medical literature. With the multi-site NT closure model, we find that the majority of NTDs can be explained by failure of fusion of one of the closures or their contiguous neuropores. We hypothesize that: Anencephaly results from failure of closure 2 for meroacranium and closures 2 and 4 for holoacranium. Spina-bifida cystica results from failure of rostral and/or caudal closure 1 fusion. Craniorachischisis results from failure of closures 2, 4, and 1. Closure 3 non-fusion is rare, presenting as a midfacial cleft extending from the upper lip through the frontal area ("facioschisis"). Frontal and parietal cephaloceles occur at the sites of the junctions of the cranial closures 3-2 and 2-4 (the prosencephalic and mesencephalic neuropores). Occipital cephaloceles result from incomplete membrane fusion of closure 4. In humans, the most caudal NT may have a 5th closure site involving L2 to S2. Closure below S2 is by secondary neurulation. Evidence for multi-site NT closure is apparent in clinical cases of NTDs, as well as in previous epidemiological studies, empiric recurrence risk studies, and pathological studies. Genetic variations of NT closures sites occur in mice and are evident in humans, e.g., familial NTDs with Sikh heritage (closure 4 and rostral 1), Meckel-Gruber syndrome (closure 4), and Walker-Warburg syndrome (2-4 neuropore, closure 4). Environmental and teratogenic exposures frequently affect specific closure sites, e.g., folate deficiency (closures 2, 4, and caudal 1) and valproic acid (closure 5 and canalization). Classification of NTDs by closure site is recommended for all studies of NTDs in humans.(ABSTRACT TRUNCATED AT 400 WORDS)