VACTERL-hydrocephaly, DK-phocomelia, and cerebro-cardio-radio-reno-rectal community

Nonfamilial VACTERL-H Syndrome in a Dizygotic Twin: Prenatal Ultrasound and Postnatal 3D CT Findings

Background: VACTERL association is a widely known congenital malformation that includes vertebral, anal, cardiac, tracheoesophageal, renal, and limb anomalies. Patients with VACTERL and hydrocephalus appear to form a distinct group, both genetically and phenotypically, and their condition has been called VACTERL-H syndrome. Most cases of VACTERL-H have been reported postnatally, as VACTER-H syndrome is difficult to diagnose prenatally. Case Presentation: Here, we report a case of VACTERL-H syndrome in a dichorionic and diamniotic twin diagnosed prenatally by ultrasonography and confirmed postnatally by three-dimensional computed tomography (3D CT). A 34-year-old multiparous female was referred to our institution at 31 + 3 weeks gestation for suspected fetal ventriculomegaly. Detailed examinations using two-dimensional and Doppler ultrasounds revealed hydrocephalus, bilateral dysplastic upper arms, radial aplasia, unilateral pulmonary agenesis, dextrocardia with right atrial enlargement, a unilateral hypoplastic ectopic kidney, a single umbilical artery, a tracheoesophageal fistula with a small stomach, polyhydramnios, and anal atresia. Findings from the postnatal 3D CT aligned with the prenatal diagnosis, showing upper-limb agenesis, dextrocardia with pulmonary hypoplasia, tracheoesophageal fistula, imperforate anus, and colon dilatation. The affected 1390-g male twin had an unaffected 1890-g female twin sister and a healthy 6-year-old brother. Conclusions: Upon encountering fetuses with multiple anomalies, including ventriculomegaly, a small stomach with polyhydramnios, an abnormally positioned heart, and upper-limb abnormalities, clinicians should perform systematic ultrasonographic examinations to detect associated anomalies and be aware of VACTERL-H syndrome.

Prenatal cannabis exposure - The "first hit" to the endocannabinoid system

As more states and countries legalize medical and/or adult recreational marijuana use, the incidences of prenatal cannabis exposure (PCE) will likely increase. While young people increasingly view marijuana as innocuous, marijuana preparations have been growing in potency in recent years, potentially creating global clinical, public health, and workforce concerns. Unlike fetal alcohol spectrum disorder, there is no phenotypic syndrome associated with PCE. There is also no preponderance of evidence that PCE causes lifelong cognitive, behavioral, or functional abnormalities, and/or susceptibility to subsequent addiction. However, there is compelling circumstantial evidence, based on the principles of teratology and fetal malprogramming, suggesting that pregnant women should refrain from smoking marijuana. The usage of marijuana during pregnancy perturbs the fetal endogenous cannabinoid signaling system (ECSS), which is present and active from the early embryonic stage, modulating neurodevelopment and continuing this role into adulthood. The ECSS is present in virtually every brain structure and organ system, and there is also evidence that this system is important in the regulation of cardiovascular processes. Endocannabinoids (eCBs) undergird a broad spectrum of processes, including the early stages of fetal neurodevelopment and uterine implantation. Delta-9-tetrahydrocannabinol (THC), the psychoactive chemical in cannabis, enters maternal circulation, and readily crosses the placental membrane. THC binds to CB receptors of the fetal ECSS, altering neurodevelopment and possibly rewiring ECSS circuitry. In this review, we discuss the Double-Hit Hypothesis as it relates to PCE. We contend that PCE, similar to a neurodevelopmental teratogen, delivers the first hit to the ECSS, which is compromised in such a way that a second hit (i.e., postnatal stressors) will precipitate the emergence of a specific phenotype. In summary, we conclude that perturbations of the intrauterine milieu via the introduction of exogenous CBs alter the fetal ECSS, predisposing the offspring to abnormalities in cognition and altered emotionality. Based on recent experimental evidence that we will review here, we argue that young women who become pregnant should immediately take a "pregnant pause" from using marijuana.

Neurocognitive profile of a young adolescent with DK phocomelia/von Voss phocomelia/von Voss Cherstvoy syndrome

DK phocomelia/von Voss Cherstvoy syndrome is a rare condition characterized by upper limb and urogenital abnormalities and various brain anomalies. Previously reported cases have noted significant developmental delays, although no formal testing of cognitive abilities has been reported. In this paper we describe results from a comprehensive neuropsychological evaluation of a 12-year-old male with DK phocomelia syndrome. Test findings indicated mild impairment in intellectual functioning, with more significant impairment in adaptive skills and academic achievement. The neuropsychological profile converged with neurological findings, showing a distinct pattern of strengths and weaknesses that suggests functional compromise of posterior brain regions with relatively well-preserved functioning of more anterior regions. Specifically, impairments were evident in perceptual reasoning, visual perception, and visuomotor integration, whereas normal or near normal functioning was evident in memory, receptive language, social cognition, attention, and most aspects of executive functioning. To our knowledge this is the first report to describe the neurocognitive profile of an individual with DK phocomelia syndrome.

A novel murine allele of Intraflagellar Transport Protein 172 causes a syndrome including VACTERL-like features with hydrocephalus

The primary cilium is emerging as a crucial regulator of signaling pathways central to vertebrate development and human disease. We identified atrioventricular canal 1 (avc1), a mouse mutation that caused VACTERL association with hydrocephalus, or VACTERL-H. We showed that avc1 is a hypomorphic mutation of intraflagellar transport protein 172 (Ift172), required for ciliogenesis and Hedgehog (Hh) signaling. Phenotypically, avc1 caused VACTERL-H but not abnormalities in left-right (L-R) axis formation. Avc1 resulted in structural cilia defects, including truncated cilia in vivo and in vitro. We observed a dose-dependent requirement for Ift172 in ciliogenesis using an allelic series generated with Ift172(avc1) and Ift172(wim), an Ift172 null allele: cilia were present on 42% of avc1 mouse embryonic fibroblast (MEF) and 28% of avc1/wim MEFs, in contrast to >90% of wild-type MEFs. Furthermore, quantitative cilium length analysis identified two specific cilium populations in mutant MEFS: a normal population with normal IFT and a truncated population, 50% of normal length, with disrupted IFT. Cells from wild-type embryos had predominantly full-length cilia, avc1 embryos, with Hh signaling abnormalities but not L-R abnormalities, had cilia equally divided between full-length and truncated, and avc1/wim embryos, with both Hh signaling and L-R abnormalities, were primarily truncated. Truncated Ift172 mutant cilia showed defects of the distal ciliary axoneme, including disrupted IFT88 localization and Hh-dependent Gli2 localization. We propose a model in which mutation of Ift172 results in a specific class of abnormal cilia, causing disrupted Hh signaling while maintaining L-R axis determination, and resulting in the VACTERL-H phenotype.

VACTERL-H syndrome: first trimester diagnosis

We present two consecutive female fetuses with identical upper limb anomalies. The first of the cases was found to have ventriculomegaly, atrial septal defect, anal atresia, narrowing of the duodenal lumen and unilateral renal agenesis at the end of the second trimester. These abnormalities were characteristic of autosomal recessive VACTERL-H syndrome. The second case was diagnosed to have absent radii and thumbs at 11 weeks. Detailed examination of fetal limbs in the first trimester screening in cases with high risk is useful for early detection of this malformation.

[Sirenomelia as a part of VACTERL association: a study of three cases]

Sirenomelia, characterized by a fusion of lower limb buds, is rare. Moreover, the coexistence of this malformation with a VACTERL sequence is exceptional. We report, here, three new observations associating these two diseases on fetuses from 14 to 26 weeks gestation. With these three new cases associating sirenomelia and VACTERL, observed in our unit and examined in light of data from the medical literature, we discuss the embryologic origin of such malformations and the nosologic frontiers between these two diseases.

Holoprosencephaly and limb reduction defects: a consideration of Steinfeld syndrome and related conditions

Individuals with holoprosencephaly (HPE) and limb reduction defects have been ascribed historically to a variety of syndromes with overlapping phenotypic features. As such, these patients are challenges for clinicians and researchers alike. In an effort to better understand this association, we reviewed our autopsy records and identified five cases of HPE with reduction defects of the limbs and other anomalies. One case appears to be the third reported instance of Steinfeld syndrome, while others represent microgastria-limb reduction sequence, VATER/VACTERL association, and an additional unique condition characterized by HPE, rhombencephalosynapsis, absent left radius, first metacarpal, and thumb, and congenital heart disease. The phenotypic heterogeneity inherent in these patients continues to complicate diagnosis, which will hopefully be simplified by continuing delineation at morphologic and especially genetic levels.

VACTERL-H with triphalangeal thumb and hypothyroidism in a female patient

The association of vertebral, cardiac, renal, limb anomalies, anal atresia, tracheo-esophageal fistula (VACTERL) with hydrocephalus (VACTERL-H) has recently been described. Both X linked and autosomal recessive forms have been described which are mostly indistinguishable clinically. Here we report a female newborn infant with hydrocephalus detected antenatally, oesophageal atresia with tracheo-oesophageal fistula, anal atresia, renal and vertebral anomalies, and triphalangeal thumb as well as primary hypothyroidism.

Distal 13q Deletion Syndrome and the VACTERL association: case report, literature review, and possible implications

We present a case of a child with del(13) (q31.1qter), VACTERL association, and penoscrotal transposition. Deletion of the distal long arm of chromosome 13 is associated with variable phenotypes. These phenotypes are divided into three clusters; each cluster represents a specific deleted segment of 13q. Individuals with deletions of a critical region at 13q32 have multiple congenital malformations that include components of the VACTERL association. Our patient had all six manifestations of VACTERL association. In addition, he had complete penoscrotal transposition, a unique malformation reported rarely in VACTERL association and only twice previously in deletion of distal 13q. We reviewed all reported cases of distal 13q deletions to date. Of these 137 patients, 15 could be classified into the VACTERL association. Ours was the only patient with distal 13q deletion and all VACTERL association features and also the only one with tracheoesophageal fistula. Neither holoprosencephaly nor the other central nervous system malformations that have been seen in individuals with distal 13q deletions were apparent in him. The patient presented here appears to be unique among individuals with distal 13q deletion. His cluster of malformations strengthens the argument that distal 13q deletion is a cause for VACTERL association, and that this causal relationship implies a syndromic form of VACTERL. In addition, this case and those ascertained from the literature suggest that penoscrotal transposition should be considered part of both the distal 13q-deletion syndrome and some forms of VACTERL association.

Radioulnar synostosis, radial ray abnormalities, and severe malformations in the male: a new X-linked dominant multiple congenital anomalies syndrome?

We describe a multiple congenital anomalies (MCA) syndrome dominantly transmitted through three generations. Radial ray abnormalities with wide variability of expression were observed in four female patients. Moreover, a 14-week-gestation male fetus had severe radial ray malformation, anencephaly, unilateral renal agenesis, and a common dorsal mesentery. Results of high-resolution karyotyping were normal in the malformed fetus and his affected mother. Furthermore, several spontaneous abortions of male fetuses had occurred in this pedigree. To our knowledge, a similar association has not been described previously. It could represent a new X-linked dominant MCA syndrome, or an autosomal dominant condition with severe expression limited to males.