Abstract During early embryogenesis, Sox2 expression distinguishes the neural plate from other embryonic domains, suggesting that the mechanism underlying the activation of the Sox2 gene is highly relevant to the development of this tissue. At the earliest stages of neural plate development, the Sox2 enhancer N1 regulates Sox2 expression in the extending posterior end of the neural plate. The N1 enhancer is initially activated in the axial stem cells, bipotential precursors of both neural and mesodermal lineages, therefore the activation does not immediately lead to Sox2 expression. A population of axial stem cells that remains in the superficial layer starts expressing Sox2, whereas another population that migrates through the primitive streak loses the N1 activity and becomes mesoderm. Multiple signaling cascades and transcription factors, including Wnt, fibroblast growth factor (FGF), bone morphogenetic protein (BMP) and Tbx6, are responsible for the regulation of Sox2 expression in axial stem cells to guide the development of the posterior neural plate and paraxial mesoderm.
Abstract Costello syndrome is a rare multiple congenital anomaly syndrome caused by heterozygous germline HRAS mutations, which is characterized by intellectual disability, growth retardation, distinctive facies, loose skin, cardiomyopathy and a preposition to malignancies. Although teeth abnormalities have been encountered in nearly two-thirds of the patients in literature, the evaluation tended to be limited to the extent which can be obtained from physical examination. We investigated detailed craniofacial, oral and dental findings in four patients with Costello syndrome. In this study, images reconstructed by multi-detector row computed tomography (MDCT) were used as substitutes for dental cast study and panoramic and lateral cephalometric radiograph studies to evaluate dental arches, tooth size, relationships between craniofacial and dental structures, and hypodontia. All four patients showed true/relative macrocephaly with facial bone hypoplasia and gingival hypertrophy. Occlusal attrition, malocclusion, small dental arches, microdontia, and convex face were noted in three patients. In addition, one patient showed dental caries, conic tooth and gingivitis, and another patient showed hypodontia. Our study suggests that craniofacial and dental abnormalities are common in Costello syndrome patients and comprehensive dental care should be provided from early infancy. To our knowledge, this is the first study of thorough craniofacial and dental evaluation by using MDCT in Costello syndrome. MDCT is a useful tool for precise evaluation of craniofacial and oral manifestations in patients with congenital anomaly/intellectual disability syndromes.
Abstract Choroid plexus, a fetal organ developing approximately from the sixth week of gestation, plays a fundamental role in developing fetal brain organization. As relatively little is known about the relationship between anomalies of choroid plexuses structure and their role in brain function, we examined cases of bifid choroid plexus (BCP) and discussed their potential association with lateral ventriculomegaly, other abnormal ultrasound findings, and their potential role as markers of fetal chromosomal abnormalities. In the present study, we described 23 cases of fetal BCP found in 2145 routine second trimester ultrasounds. For each patient 2D and 3D ultrasound volumes were acquired. BCP was defined as a choroid plexus whose body was divided into two portions (arms) differently located and oriented on the three spatial axes in correspondence to the lateral ventricle, in one or both sides. The entity of the separation and reciprocal orientation of the two arms was examined. The presence of BCP in a low-risk population of pregnant women undergoing routine second trimester ultrasound was showed. Lateral ventricles significantly increased in the presence of BCP. Malformations were found in four of 23 fetuses with BCP. Pregnancy outcome was favorable only in one of these four cases. We suggest that in the presence of mono or bilateral BCP without associated abnormal ultrasound findings, a closer look at fetal brain or extra-cranial structures is recommended. If no related abnormalities are found, serial prenatal and postnatal sonographic follow-up should be considered. In the presence of concomitant abnormal findings, genetic counseling, fetal karyotyping and magnetic resonance imaging, if possible by gestational age, are strongly advised.
Abstract We conducted a study of Kirner's deformity to investigate its radiologic features and consider its possible causes. Sixty-seven patients with Kirner's deformity, 41 in our series and 26 retrieved in a survey of the literature were investigated. We divided Kirner's deformity into three types according to the site of curvature: the epiphyseal line, diaphysis, and distal tip. Among our series, 12 hands were affected in males and 26 in females. The gender of the patients for the other three hands was unknown. Twelve cases occurred on the right side, five on the left side, and 24 on both sides. Radiographic data for 34 hands were available. The palmar surface of the distal phalanx was at a mean angle of 27.4 degrees to the long axis of the middle phalanx. Epiphyseal line curvature was seen in four hands (mean patient age, 11 years), diaphysis curvature in 10 (mean age, 12.4 years), and distal tip curvature in 20 (mean age, 26.5 years). Dorsal subluxation of the distal phalanx was noticed in six hands (18%). Radiographic data for 26 hands reported previously were analyzable. The differences between epiphyseal line or diaphysis curvature and distal tip curvature in terms of age were significant in both the present study and the literature.
Abstract Fibroblast growth factor (FGF) signaling is involved in skeletal development. Among total 22 FGFs, it is suggested that FGF18 functions in promotion of osteoblast differentiation. In order to elucidate the mechanism of FGF18-dependent acceleration of osteogenesis, we implanted rhFGF18 soaked beads over mouse fetal coronal sutures using ex-utero surgery. The coronal suture area comprises the peripheries of the developing frontal and parietal bones, separated by the sutural mesenchyme. rhFGF18 accelerated osteogenesis by promoting connection of the frontal and parietal bone domains, resulting in elimination of the sutural mesenchyme. Expression of Fgf receptors, Fgfr1, -2 and -3 involved in skeletal development, was maintained or upregulated in the developing bone domains, consistent with enhanced osteogenesis. Bone morphogenetic protein (Bmp) 2 was specifically upregulated in the skeletogenic layer and the application of Bmp antagonist, rmNoggin, inhibited rhFGF18-dependent upregulation of osteoblast markers. These results suggest that FGF18 accelerates osteogenesis by upregulation of Bmp2 as well as maintenance or upregulation of Fgfr1, -2 and -3 expression in osteoblasts.
Abstract The aim of this study was to test if prenatal cytogenetic diagnosis can be performed on fetal urine in fetal lower urinary tract obstruction. In this retrospective cohort study of fetuses with lower urinary tract obstruction (LUTO) over a 4-year period at one institution, cytogenetic evaluation was attempted on fetal urine samples as well as amniotic fluid specimens. A total of 11 cases, ranging in gestational age from 15 to 25 weeks, underwent amniocentesis and vesicocentesis. Traditional cytogenetic evaluation was successfully completed in amniotic fluid and fetal urine samples in all 11 cases (100%). The karyotype was normal in seven (64%), trisomy 21 in two (18%), Trisomy 13 in one (9%), and partial chromosome 4 deletion in one (9%). Traditional cytogenetic evaluation can be successfully performed on fetal urine samples in cases of lower urinary tract obstruction.
Abstract Sacrococcygeal teratoma (SCT) is a rare congenital disease and prognostic factors have not been entirely established. We report two cases of fetal SCT with different clinical courses. Case 1 was a cystic, slow growing tumor with mild vascularity. The tumor was removed one week after delivery at 35 weeks, and there was no recurrence at 1.5-year follow-up. Case 2 was a solid, rapid growing tumor with rich vascularity. Cesarean section was performed due to severe fetal hydrops and mirror syndrome in the mother at 27 weeks. The tumor had ruptured and was removed soon after delivery to control bleeding, but the baby died the next day. Our cases suggest that solid component and rich vascularity might correlate with poor prognosis.
ABSTRACT We report a rare case of a monochorionic twin gestation after intracytoplasmic sperm injection (ICSI) in which one of the fetuses had VACTERL association. A 27-year-old woman became pregnant by ICSI and was found to have monochorionic twin fetuses. One fetus was noted to have the following anomalies: a multicystic, dysplastic left kidney with a hydroureter, and a dilated colon. A normal-sized stomach and normal amount of amniotic fluid were observed during the prenatal period with no other anomalies. The postnatal examination revealed hypospadias, and anal, esophageal, and duodenal atresia; thus, a diagnosis of VACTERL association was established. Although the prenatal diagnosis of this disorder is a challenge, even in a singleton, some of the characteristic features observed during antepartum ultrasonography may be a clue to the diagnosis, especially in a twin pregnancy after ICSI.