Nucleolar URB1 ensures 3' ETS rRNA removal to prevent exosome surveillance.

The nucleolus is the most prominent membraneless condensate in the nucleus. It comprises hundreds of proteins with distinct roles in the rapid transcription of ribosomal RNA (rRNA) and efficient processing within units comprising a fibrillar centre and a dense fibrillar component and ribosome assembly in a granular component1. The precise localization of most nucleolar proteins and whether their specific localization contributes to the radial flux of pre-rRNA processing have remained unknown owing to insufficient resolution in imaging studies2-5. Therefore, how these nucleolar proteins are functionally coordinated with stepwise pre-rRNA processing requires further investigation. Here we screened 200 candidate nucleolar proteins using high-resolution live-cell microscopy and identified 12 proteins that are enriched towards the periphery of the dense fibrillar component (PDFC). Among these proteins, unhealthy ribosome biogenesis 1 (URB1) is a static, nucleolar protein that ensures 3' end pre-rRNA anchoring and folding for U8 small nucleolar RNA recognition and the subsequent removal of the 3' external transcribed spacer (ETS) at the dense fibrillar component-PDFC boundary. URB1 depletion leads to a disrupted PDFC, uncontrolled pre-rRNA movement, altered pre-rRNA conformation and retention of the 3' ETS. These aberrant 3' ETS-attached pre-rRNA intermediates activate exosome-dependent nucleolar surveillance, resulting in decreased 28S rRNA production, head malformations in zebrafish and delayed embryonic development in mice. This study provides insight into functional sub-nucleolar organization and identifies a physiologically essential step in rRNA maturation that requires the static protein URB1 in the phase-separated nucleolus.

Involvement of the centrosomal protein 55 (cep55) gene in zebrafish head formation.

Mammalian CEP55 (centrosomal protein 55 kDa) is a coiled-coil protein localized to the centrosome in interphase cells and is required for cytokinesis. A homozygous non-sense mutation in human CEP55 has been recently identified in perinatal lethal MARCH (multinucleated neurons, anhydramnios, renal dysplasia, cerebellar hypoplasia and hydranencephaly) syndrome. We have isolated zebrafish cep55 mutants defective in head morphology. The zebrafish cep55 gene was expressed in the head including the retina and the pectoral fin at 1 day post-fertilization (dpf), and extensive cell death was widely observed in the head and tail of the cep55 mutant. In the cep55 mutant, the anterior-posterior distance of the ventral pharyngeal arches was short, and retinal lamination was disorganized. Neural cells, such as islet1-positive cells and pax2-positive cells, and fli1b-positive vascular cells were reduced in the head of the cep55 mutant. Thus, we propose that the zebrafish cep55 mutant is a model organism for human MARCH syndrome.

Social, neurodevelopmental, endocrine, and head size differences associated with atypical deletions in Williams-Beuren syndrome.

Williams-Beuren syndrome (WBS) is a multisystem disorder caused by a hemizygous deletion on 7q11.23 encompassing 26-28 genes. An estimated 2-5% of patients have "atypical" deletions, which extend in the centromeric and/or telomeric direction from the WBS critical region. To elucidate clinical differentiators among these deletion types, we evaluated 10 individuals with atypical deletions in our cohort and 17 individuals with similarly classified deletions previously described in the literature. Larger deletions in either direction often led to more severe developmental delays, while deletions containing MAGI2 were associated with infantile spasms and seizures in patients. In addition, head size was notably smaller in those with centromeric deletions including AUTS2. Because children with atypical deletions were noted to be less socially engaged, we additionally sought to determine how atypical deletions relate to social phenotypes. Using the Social Responsiveness Scale-2, raters scored individuals with atypical deletions as having different social characteristics to those with typical WBS deletions (p = .001), with higher (more impaired) scores for social motivation (p = .005) in the atypical deletion group. In recognizing these distinctions, physicians can better identify patients, including those who may already carry a clinical or FISH WBS diagnosis, who may benefit from additional molecular evaluation, screening, and therapy. In addition to the clinical findings, we note mild endocrine findings distinct from those typically seen in WBS in several patients with telomeric deletions that included POR. Further study in additional telomeric deletion cases will be needed to confirm this observation.

Self-compounded Doxycycline Sclerotherapy for the Treatment of Lymphatic Malformations in Low-Resource Settings.

BACKGROUND: Congenital anomalies are one component of the overwhelming surgical disease burden in low- and middle-income countries (LMICs). Lymphatic malformations (LMs) are a common congenital deformity of the head and neck in which the utilization of sclerotherapy may avoid surgery and yield superior outcomes. To be useful in LMICs, sclerosing agents must be widely available, inexpensive, and effective. METHODS: A retrospective review of 10 pediatric patients with macrocystic or mixed LMs who were treated with self-compounded doxycycline sclerotherapy at Rwanda's Central University Teaching Hospital of Kigali was performed. Doxycycline oral tablets were crushed by hand, mixed with normal saline at a concentration of doxycycline 10 mg/mL, and injected directly into LMs of the head and neck. RESULTS: Ten pediatric patients underwent 21 sclerotherapy sessions with a mean of 2.1 sessions per patient (SD 1.3, range 1-5). Of the 8 patients that were seen in follow-up, all achieved at least 80% resolution, 6 of 8 achieved 100% resolution, and none required surgery. One patient developed an infection at the injection site which resolved with antibiotics. CONCLUSIONS: Self-compounded doxycycline sclerotherapy is a safe, effective, and widely available treatment option for sclerotherapy of LMs in LMICs.

De Novo Mutations in SON Disrupt RNA Splicing of Genes Essential for Brain Development and Metabolism, Causing an Intellectual-Disability Syndrome.

The overall understanding of the molecular etiologies of intellectual disability (ID) and developmental delay (DD) is increasing as next-generation sequencing technologies identify genetic variants in individuals with such disorders. However, detailed analyses conclusively confirming these variants, as well as the underlying molecular mechanisms explaining the diseases, are often lacking. Here, we report on an ID syndrome caused by de novo heterozygous loss-of-function (LoF) mutations in SON. The syndrome is characterized by ID and/or DD, malformations of the cerebral cortex, epilepsy, vision problems, musculoskeletal abnormalities, and congenital malformations. Knockdown of son in zebrafish resulted in severe malformation of the spine, brain, and eyes. Importantly, analyses of RNA from affected individuals revealed that genes critical for neuronal migration and cortex organization (TUBG1, FLNA, PNKP, WDR62, PSMD3, and HDAC6) and metabolism (PCK2, PFKL, IDH2, ACY1, and ADA) are significantly downregulated because of the accumulation of mis-spliced transcripts resulting from erroneous SON-mediated RNA splicing. Our data highlight SON as a master regulator governing neurodevelopment and demonstrate the importance of SON-mediated RNA splicing in human development.

An analysis of body proportions in children with CHARGE syndrome using photogrammetric anthropometry.

BACKGROUND: Growth retardation is one of the main hallmarks of CHARGE syndrome (CS), yet little is known about the body proportions of these children. Knowledge of body proportions in CS may contribute to a better characterization of this syndrome. This knowledge is important when considering starting growth-stimulating therapy. METHODS: For this cross-sectional study, we selected 32 children with CS and a CHD7 mutation at the Dutch CHARGE Family Day in 2016 or 2017 and the International CHARGE conference in Orlando, Florida, in 2017. We used photogrammetric anthropometry-a measurement method based on digital photographs-to determine various body proportions. We compared these to measurements in 21 normally proportioned children with growth hormone deficiency, using independent-samples t test, Mann-Whitney U test, or chi-square test as appropriate. RESULTS: Children with CS appear to have a shorter trunk in proportion to their height, head length, and arm length. Children with CS also had smaller feet proportional to tibia length compared to controls. The change of body proportions with age was similar in children with CS and controls. CONCLUSION: Body proportions in children with CS are significantly different from those of normally proportioned controls, but a similar change of body proportions with age was noted for both groups.

Second-trimester fetal head circumference in more than 350 000 pregnancies: Outcome and suggestion for sex-dependent cutoffs for small heads.

OBJECTIVE: To explore the relationship between small fetal second-trimester head circumference (HC) and pregnancy outcome and identify a cutoff point for offering genetic testing. METHOD: Data from second-trimester scans in Denmark were linked to national registers. Fetuses with anomalies diagnosed before this scan were excluded. Fetuses were grouped according to HC z-score. RESULTS: We included 352 515 singleton fetuses. The mean HC was significantly larger among males than among females with z-scores averaging 0.52 more in males. Small HC was associated with chromosomal anomaly, malformations of the CNS and heart, miscarriage/perinatal death, termination, preterm delivery, and intrauterine growth restriction (test for trend: P < .001 for all outcomes). Fetuses in the group with z-score less than -3 had the highest incidence of adverse outcome, irrespective of fetal sex. In the groups with z-scores between -3 and -2.5, and between -2.5 and -2, risk of adverse outcome was lower for females than males for all outcome categories. CONCLUSION: Small HC in second trimester is a prognostic marker for adverse outcome. The smaller the HC, the higher the risk of adverse outcome. We suggest an HC cutoff point of -2 SD for males and -2.5 SD for females for offering genetic testing.

Soft Tissue Reconstruction and Facial Reanimation With Bilateral Latissimus Dorsi Flaps After Extensive Resection of Head and Neck Arteriovenous Malformation: A Case Report.

We report a rare case of a 37-year-old man who presented with a huge arteriovenous malformation in the head and neck region. After resection, the 30 × 25 cm defect was reconstructed with a preexpanded musculocutaneous latissimus dorsi flap. The facial nerve had to be sacrificed during the resection, and smile reanimation was restored in a second operation with the contralateral latissimus muscle flap. A 15-cm length of thoracodorsal nerve was dissected and was anastomosed to the contralateral zygomatic branch in a single stage. He recovered well without any significant complications. At 6 years follow-up, there was no further growth of the arteriovenous malformation, and he had a spontaneous smile.

Flat Head Syndrome in Infants.

This JAMA Patient Page describes the types of flat head syndrome and its prevention and treatment.

External and computed tomography analysis of a strophocephalic lamb.

CONTEXT: The Museum of Anatomy and Embryology Louis Deroubaix attached to the Laboratory of Anatomy, Biomecanics and Organogenesis, ULB, Brussels, possesses in its liquid collections a cephalic extremity of a lamb suffering from strophocephaly. The origins have not been determined. The trunk and the limbs are resected. MATERIAL AND METHODS: The piece has been studied and photographed. A volumic computed tomography acquisition has been performed with a Siemens Volume Zoom. For pedagogic and museological purposes, surface reconstructions and 3D printing have been obtained. RESULTS: An otocephaly is observed. Both ears are located in place of the oral cavity. The mandible is welded to the braincase. The eyeballs are close together (synophtalmia) which confirms the presence of a cyclotocephaly. They are surmounted by a rudimentary snout rather than a proboscis. The presence of this muzzle allows the anomaly to be classified as a strophocephaly, a malformation already described in sheeps. CT slices of the brain show a semi-lobar holoprosencephaly with incomplete division of the cerebral hemispheres and ventricules. DISCUSSION AND CONCLUSION: The CT examination allows the facial anomalies to be allocated to a holoprosencephaly. The singularity of this case, compared to the human cyclotocephalies, is the presence of a differentiated muzzle rather than a simple proboscis. The holoprosencephaly is uncomplete. Such anomalies have been associated with an entire absence of cerebral differentiation but with a complete absence of the muzzle. The tridimensional printing represents an interesting educational tool easily transportable in contrast to the original specimen.

KCTD13 is a major driver of mirrored neuroanatomical phenotypes of the 16p11.2 copy number variant.

Copy number variants (CNVs) are major contributors to genetic disorders. We have dissected a region of the 16p11.2 chromosome--which encompasses 29 genes--that confers susceptibility to neurocognitive defects when deleted or duplicated. Overexpression of each human transcript in zebrafish embryos identified KCTD13 as the sole message capable of inducing the microcephaly phenotype associated with the 16p11.2 duplication, whereas suppression of the same locus yielded the macrocephalic phenotype associated with the 16p11.2 deletion, capturing the mirror phenotypes of humans. Analyses of zebrafish and mouse embryos suggest that microcephaly is caused by decreased proliferation of neuronal progenitors with concomitant increase in apoptosis in the developing brain, whereas macrocephaly arises by increased proliferation and no changes in apoptosis. A role for KCTD13 dosage changes is consistent with autism in both a recently reported family with a reduced 16p11.2 deletion and a subject reported here with a complex 16p11.2 rearrangement involving de novo structural alteration of KCTD13. Our data suggest that KCTD13 is a major driver for the neurodevelopmental phenotypes associated with the 16p11.2 CNV, reinforce the idea that one or a small number of transcripts within a CNV can underpin clinical phenotypes, and offer an efficient route to identifying dosage-sensitive loci.

Determination of developmental toxicity of zebrafish exposed to propyl gallate dosed lower than ADI (Acceptable Daily Intake).

Propyl gallate (PG) is an antioxidant substance widely used in cosmetics, pharmaceutical and food industries. The aim of this study was to evaluate the potential toxic effect of PG injected to zebrafish embryos. To this end, zebrafish embryos were exposed to PG with 0, 1, 10 and 50 ppm concentrations which are lower than ADI and were monitored at 24, 48, 72 and 96 hpf. Survival rate, hatching rate and malformations were evaluated during this period. Moreover, it has been detected the accumulation of fluorescence signal of ROS and apoptotic cell in whole body at the end of 96 hpf. According to results, survival rate slightly decreased in highest concentration, and PG accelerated hatching in 1 and 10 ppm concentrations whereas delayed in 50 ppm concentration. In addition, it has been detected accumulation of fluorescence signal of ROS and apoptotic cells in a dose dependent-manner. Consequently, it has been considered that increased embryonic or larval malformation in this study may have been caused by ROS-induced apoptosis. The obtained data suggested that the developmental toxicity caused by PG and/or multiple hydroxyl groups arose when PG hydrolyze to gallic acid is probably triggered by the induction of ROS formation and consequent apoptosis.

Dissection of the complex genetic basis of craniofacial anomalies using haploid genetics and interspecies hybrids in Nasonia wasps.

The animal head is a complex structure where numerous sensory, structural and alimentary structures are concentrated and integrated, and its ontogeny requires precise and delicate interactions among genes, cells, and tissues. Thus, it is perhaps unsurprising that craniofacial abnormalities are among the most common birth defects in people, or that these defects have a complex genetic basis involving interactions among multiple loci. Developmental processes that depend on such epistatic interactions become exponentially more difficult to study in diploid organisms as the number of genes involved increases. Here, we present hybrid haploid males of the wasp species pair Nasonia vitripennis and Nasonia giraulti, which have distinct male head morphologies, as a genetic model of craniofacial development that possesses the genetic advantages of haploidy, along with many powerful genomic tools. Viable, fertile hybrids can be made between the species, and quantitative trail loci related to shape differences have been identified. In addition, a subset of hybrid males show head abnormalities, including clefting at the midline and asymmetries. Crucially, epistatic interactions among multiple loci underlie several developmental differences and defects observed in the F2 hybrid males. Furthermore, we demonstrate an introgression of a chromosomal region from N. giraulti into N. vitripennis that shows an abnormality in relative eye size, which maps to a region containing a major QTL for this trait. Therefore, the genetic sources of head morphology can, in principle, be identified by positional cloning. Thus, Nasonia is well positioned to be a uniquely powerful model invertebrate system with which to probe both development and complex genetics of craniofacial patterning and defects.

The diagnostic yield of ultrasound of the head in healthy infants presenting with the clinical diagnosis of benign macrocrania.

AIM: To investigate the frequency of sonographic findings that required neurosurgical consultation for all referred outpatients suspected to have benign macrocrania (BMC). MATERIALS AND METHODS: A retrospective review was performed from September 2011 until June 2015 for all outpatients referred to the ultrasound (US) department for BMC. Electronic medical records, US images, and reports were reviewed in conjunction with follow-up imaging. Each review consisted of gender, specialty of referring physician, first head circumference, head circumference at or closest to the time of the head US, the last head circumference, and any neurological issue prior to the US, at the time of US, or following the US, and clinical outcomes. Statistical analysis employed the Kruskal-Wallis rank sum test and Fischer's exact test (chi square test of independence) that compared normal/BMC patients from the patients requiring a neurosurgical consultation. RESULTS: One hundred and thirty (40.9%) had a normal head US, 181 patients (56.9%) had sonographic findings of BMC, and seven (2.2%) patients had an abnormal head US that required a neurosurgical consultation. Of the 181 patients with BMC, 23 underwent follow-up imaging with 22 patients having unchanged BMC or a normal head US and one patient developing mild ventriculomegaly that was stable on follow-up imaging. Three of the seven patients (1%) aged 1.8, 2.3, and 13.1 months with abnormal head US requiring neurosurgical consultation, had mild ventriculomegaly that was stable on follow-up imaging. Four of the seven patients (1.2%) that required neurosurgical consultation needed a neurosurgical procedure. Between the two US subgroups (normal and BMC), no statistical significance was noted regarding age of patient at US, head circumference at clinical and radiological presentation (p>0.05) except for the first head circumference clinically documented which demonstrated statistical significance (p<0.03). CONCLUSION: Short interval surveillance including head circumference and assessment for the development of bulging anterior fontanelle and neurological abnormalities may be more cost effective than US in the initial evaluation of patients clinically suspected to have BMC.

[Management of positional head deformity in 31 infants].

OBJECTIVE: To investigate the clinical effect of postural correction training and helmet therapy in the treatment of moderate-severe positional head deformity defined as asymmetric head shape in infants. METHODS: A total of 31 infants who were diagnosed with moderate-severe plagiocephaly and/or brachiocephaly were enrolled. According to the different treatment methods, the infants were divided into helmet therapy group with 11 infants and postural correction training group with 20 infants. The cranial vault asymmetry index (CVAI), cephalic ratio (CR), and head circumference growth were compared between the two groups before and after treatment. RESULTS: Compared with the postural correction training group, the helmet therapy group had significantly lower CVAI and CR after treatment. The helmet therapy group had significantly better improvements in CVAI and CR after treatment compared with the postural correction training group (CVAI difference: 6.0±1.9 vs 0.7±0.8, P=0.001; CR difference: 0.047±0.009 vs 0.008±0.005, P<0.001). There was no significant difference in head circumference growth between the two groups (P=0.55). CONCLUSIONS: Helmet therapy has a significantly better effect in the treatment of moderate-severe positional head deformity than postural correction training in infants. Helmet therapy does not limit head circumference growth.

The society for craniofacial genetics and developmental biology 38th annual meeting.

The mission of the Society for Craniofacial Genetics and Developmental Biology (SCGDB) is to promote education, research, and communication about normal and abnormal development of the tissues and organs of the head. The SCGDB welcomes as members undergraduate students, graduate students, post doctoral researchers, clinicians, orthodontists, scientists, and academicians who share an interest in craniofacial biology. Each year our members come together to share their novel findings, build upon, and challenge current knowledge of craniofacial biology. © 2016 Wiley Periodicals, Inc.

Reconstructive algorithms in the pediatric population.

Reconstruction of oncologic defects in the pediatric population is a unique challenge. Differences in patient comorbidities, size of the reconstructive components, response of the skeletally immature body to surgery and radiation, compliance, and overall recovery potential make the pediatric patient cohort distinct from the adult population. Considering that patients are enjoying longer life spans, it behooves the surgeon to reconstruct oncologic defects with durable and long-lasting tissue. Determining when to implement each of the reconstructive tools is based upon principles embodied by the reconstructive ladder and taking into account the defect-specific characteristics, including location and type of tissues involved. Within the setting of multi-disciplinary care, reconstruction can be associated with good long-term functional and aesthetic outcomes. J. Surg. Oncol. 2016;113:940-945. © 2016 Wiley Periodicals, Inc.

Campylorrhinus lateralis, Bilateral microphthalmia and odontoma temporalis in an Oldenburg Foal.

An Oldenburg colt with wry nose was autopsied after having lived for only 30 min. It presented cyanotic oral mucosae, underdeveloped eyes and a right-sided temporal osseous mass. The applicable nomenclature for the defects is discussed, and the potential etiopathogenesis is explored by describing the normal embryonic development of the affected body parts.

[Lymphatic malformations in the head and neck area]. / Lymphatische Malformationen im Kopf-Hals-Bereich.

Lymphatic malformations are congenital malformations of the lymphatic system. They are mainly located in the head and neck area, and grow proportional to the patients' body growth. Depending on the morphology, it can be distinguished between macrocystic, microcystic and mixed lymphatic malformations. Due to their infiltrative growth, microcystic lymphatic malformations are particularly difficult to treat. Therapeutic approaches include conventional surgical resection, laser therapy, sclerotherapy and systemic drug therapies.