Intellectual Functioning of Children With Isolated PRS, PRS-Plus, and Syndromic PRS

OBJECTIVE

Describe the intelligence quotient (IQ) of children with Pierre Robin sequence (PRS).

DESIGN

Prospective cohort study.

SETTING

Neurodevelopmental follow-up clinic within a hospital.

PATIENTS

Children with PRS (n = 45) who had been in the Neonatal Intensive Care Unit (NICU) were classified by a geneticist into 3 subgroups of isolated PRS (n = 20), PRS-plus additional medical features (n = 8), and syndromic PRS (n = 17) based on medical record review and genetic testing.

MAIN OUTCOME MEASURE

Children with PRS completed IQ testing at 5 or 8 years of age with the Wechsler Preschool and Primary Scale of Intelligence, Third Edition (WPPSI-III) or Fourth Edition (WPPSI-IV) or the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV) or Fifth Edition (WISC-V).

RESULTS

IQ scores were more than 1 to 2 standard deviations below the mean for 36% of the overall sample, which was significantly greater compared to test norms (binomial test P = .001). There was a significant association between PRS subtype and IQ (Fisher's exact P = .026). While only 20% of children with isolated PRS were within 1 standard deviation below average and 35% of children with syndromic PRS were below 1 to 2 standard deviations, 75% of PRS-plus children scored lower than 1 to 2 standard deviations below the mean.

CONCLUSION

PRS subgroups can help identify children at risk for cognitive delay. The majority of children with PRS-plus had low intellectual functioning, in contrast to the third of children with syndromic PRS who had low IQ and the majority of children with isolated PRS who had average or higher IQ.

A TARP Syndrome Phenotype Is Associated with a Novel Splicing Variant in RBM10

TARP syndrome (Talipes equinovarus, Atrial septal defect, Robin sequence, and Persistence of the left superior vena cava) is a rare genetic condition, caused by developmental defects during embryogenesis. The phenotypic spectrum of TARP shows high clinical variability with patients either missing cardinal features or having additional clinical traits. Initially, TARP was considered a lethal syndrome, but patients with milder symptoms were recently described. The TARP-locus was mapped to the gene RNA-binding motif protein 10 (RBM10) on the human X-chromosome. We clinically and genetically described a six-year-old boy with a TARP-phenotype. Clinical heterogeneity of symptoms prompted us to sequence the entire exome of this patient. We identified a novel splice variant (NM_005676: c.17+1G>C, p.?) in RBM10. A patient-derived cell line was used to verify the pathogenicity of the RBM10 splice variant by RNA analyses, Western blotting, and immunofluorescence staining. Our molecular genetic findings together with the analyses of progressing clinical symptoms confirmed the diagnosis of TARP. It seems essential to analyze correlations between genotype, phenotype, and molecular/cellular data to better understand RBM10-associated pathomechanisms, assist genetic counseling, and support development of therapeutic approaches.

Humidified versus nonhumidified low-flow oxygen therapy in children with Pierre-Robin syndrome: A randomized controlled trial

BACKGROUND

Humidification is an important process in clinical oxygen therapy. We aimed to evaluate the effects and safety of humidified versus nonhumidified low-flow oxygen therapy in children with Pierre-Robin syndrome.

METHODS

This study was an open-label, single-centered randomized controlled trial (RCT) with a parallel group design. The study protocol has been registered in Chinese Clinical Trial Registry (ChiCTR1900021584). The children were randomized to the humidified versus nonhumidified groups. Average arterial oxygen partial pressure (PaO2) and carbon dioxide partial pressure (PaCO2), incidence of ventilator-associated pneumonia (VAP), nasal cavity dryness, nasal mucosal bleeding and bacterial contamination of the humidified bottle, the cost of nasal oxygen therapy and duration of intensive care unit (ICU) stay were analyzed.

RESULTS

A total of 213 children with Pierre-Robin syndrome were included. There were no significant differences in the gender, age, weight, prematurity, duration of anesthesia and surgery duration of mandibular traction between humidified group and nonhumidified group (all P > .05). No significant differences in the average arterial PaO2 and PaCO2 level on the postoperative day 1, 2, and ICU discharge between humidified group and nonhumidified group were found (all P > .05). There were no significant differences in the incidence of nasal cavity dryness, nasal mucosal bleeding, bacterial contamination and VAP, the duration of ICU stay between humidified group and nonhumidified group (all P > .05). The cost of nasal oxygen therapy in the humidified group was significantly less than that of nonhumidified group (P = .013).

CONCLUSIONS

Humidifying the oxygen with cold sterile water in the low-flow oxygen therapy in children may be not necessary. Future RCTs with lager sample size and rigorous design are warranted to further elucidate the effects and safety of humidified versus nonhumidified low-flow oxygen therapy.

Impaired activity of the fusogenic micropeptide Myomixer causes myopathy resembling Carey-Fineman-Ziter syndrome

Skeletal muscle fibers contain hundreds of nuclei, which increase the overall transcriptional activity of the tissue and perform specialized functions. Multinucleation occurs through myoblast fusion, mediated by the muscle fusogens Myomaker (MYMK) and Myomixer (MYMX). We describe a human pedigree harboring a recessive truncating variant of the MYMX gene that eliminates an evolutionarily conserved extracellular hydrophobic domain of MYMX, thereby impairing fusogenic activity. Homozygosity of this human variant resulted in a spectrum of abnormalities that mimicked the clinical presentation of Carey-Fineman-Ziter syndrome (CFZS), caused by hypomorphic MYMK variants. Myoblasts generated from patient-derived induced pluripotent stem cells displayed defective fusion, and mice bearing the human MYMX variant died perinatally due to muscle abnormalities. In vitro assays showed that the human MYMX variant conferred minimal cell-cell fusogenicity, which could be restored with CRISPR/Cas9-mediated base editing, thus providing therapeutic potential for this disorder. Our findings identify MYMX as a recessive, monogenic human disease gene involved in CFZS, and provide new insights into the contribution of myoblast fusion to neuromuscular diseases.

Fetal markers for the detection of infants with craniofacial malformation

Facial clefts and Robin sequence (RS) share the timing of the diagnosis during the course of pregnancy, their association with genetic diseases and the subsequent management following the initial diagnosis. If a suspicion of a facial cleft or RS is made, a detailed anatomical examination of the fetus should be carried out to identify further anomalies. This may also involve genetic testing including a microarray or an exome analysis. Interdisciplinary counseling, including pre- and postnatal experts with sufficient experience in the management of such neonates, should be involved in this counseling. Parents should be informed about disease-specific therapeutic options and postnatal outcome. Delivery should take place in a center with experience in craniofacial malformations where clinicians are prepared for potentially life-threatening airway obstruction immediately after birth.

Respiratory Failure in a Neonate with Pierre Robin Syndrome -A Challenging Proposition

Background Fine needle aspiration (FNA) with radiological assisted tools such as ultrasonography (USG) and computed tomography (CT) are effective in obtaining high yield aspiration of tissues located in technically difficult places such as deep-seated. It is a simple outpatient procedure with low cost as compared to surgical biopsies. Objective To study the cytomorphological features of deep-seated lesions according to the site of occurrence, and to categorize them with respect to age, sex and behavior of lesions. Method This was a descriptive cross-sectional study of 125 patients who underwent imageguided fine needle aspiration cytology of deep-seated lesions. The study was conducted in the Department of Pathology and Department of Radiodiagnosis, Dhulikhel Hospital- Kathmandu University Hospital, between January 2017 and December 2018. Under radiological guidance, aspiration was performed under negative pressure, and adequate material was obtained. Smears were stained with Giemsa and Papanicolaou stain. The prepared slides were examined under a microscope. Result Of the 125 patients who underwent USG and CT-guided fine needle aspiration cytology (FNAC), 68(54.4%) were female and 57(45.6%) were male. The age of the patients ranged from 13 to 84 years. The maximum number of patients was above 50 years. The nature of lesions was categorized as malignant 78(62.4%), followed by 23(18.4%) inflammatory and benign 1(0.8%). Conclusion Image-guided fine needle aspiration cytology is a safe diagnostic procedure, as it provides real-time visualization of tip insertion in anatomical structures. It provides high yield and a better representation of the samples.

Loss of Extreme Long-Range Enhancers in Human Neural Crest Drives a Craniofacial Disorder

Non-coding mutations at the far end of a large gene desert surrounding the SOX9 gene result in a human craniofacial disorder called Pierre Robin sequence (PRS). Leveraging a human stem cell differentiation model, we identify two clusters of enhancers within the PRS-associated region that regulate SOX9 expression during a restricted window of facial progenitor development at distances up to 1.45 Mb. Enhancers within the 1.45 Mb cluster exhibit highly synergistic activity that is dependent on the Coordinator motif. Using mouse models, we demonstrate that PRS phenotypic specificity arises from the convergence of two mechanisms: confinement of Sox9 dosage perturbation to developing facial structures through context-specific enhancer activity and heightened sensitivity of the lower jaw to Sox9 expression reduction. Overall, we characterize the longest-range human enhancers involved in congenital malformations, directly demonstrate that PRS is an enhanceropathy, and illustrate how small changes in gene expression can lead to morphological variation.

[The significance of evaluation of sleep respiration in infants with Pierre Robin sequence]

Objective:This study aimed to evaluate the sleep disorders of infants with Pierre Robin sequence by PSG, and to understand the sleep breathing characteristics of them. Method:Seventeen patients with Pierre Robin sequence underwent polysomnography lasting over 7 hours. Sleep apnea and oxygen index was recorded and analyzed. Result:14（82.35%） patients with Pierre Robin sequence presented with apnea, hypopnea and hypoxemia with varying degree. The apnea-hypopnea index（12.39±9.86） and lowest arterial oxygen saturation（84.12±8.12） %were not significantly different between sexes. However, age showed a negative impact with apnea-hypopnea index, which was worse in younger infants. Conclusion:Most patients with the Pierre Robin sequence have sleep apnea and hypoxemia, and appropriate management should be implemented in an early age. Polysomnography can provide objective analysis of the treatment.

Biallelic variants in KYNU cause a multisystemic syndrome with hand hyperphalangism

Catel-Manzke syndrome is characterized by the combination of Pierre Robin sequence and radial deviation, shortening as well as clinodactyly of the index fingers, due to an accessory ossification center. Mutations in TGDS have been identified as one cause of Catel-Manzke syndrome, but cannot be found as causative in every patient with the clinical diagnosis. We performed a chromosome microarray and/or exome sequencing in three patients with hand hyperphalangism, heart defect, short stature, and mild to severe developmental delay, all of whom were initially given a clinical diagnosis of Catel-Manzke syndrome. In one patient, we detected a large deletion of exons 1-8 and the missense variant c.1282C > T (p.Arg428Trp) in KYNU (NM_003937.2), whereas homozygous missense variants in KYNU were found in the other two patients (c.989G > A (p.Arg330Gln) and c.326G > C (p.Trp109Ser)). Plasma and urine metabolomic analysis of two patients indicated a block along the tryptophan catabolic pathway and urine organic acid analysis showed excretion of xanthurenic acid. Biallelic loss-of-function mutations in KYNU were recently described as a cause of NAD deficiency with vertebral, cardiac, renal and limb defects; however, no hand hyperphalangism was described in those patients, and Catel-Manzke syndrome was not discussed as a differential diagnosis. In conclusion, we present unrelated patients identified with biallelic variants in KYNU leading to kynureninase deficiency and xanthurenic aciduria as a very likely cause of their hyperphalangism, heart defect, short stature, and developmental delay. We suggest performance of urine organic acid analysis in patients with suspected Catel-Manzke syndrome, particularly in those with cardiac or vertebral defects or without mutations in TGDS.

Macrodontia Associated with Mandibular Distraction Osteogenesis

Infants diagnosed with Pierre Robin sequence frequently have airway obstruction. In severe cases of obstruction, mandibular distraction osteogenesis (MDO) can alleviate the airway blockage through elongation of the mandible and subsequent anterior placement of the tongue. However, there are several complications associated with MDO in the very young child. Among those are injuries to teeth that develop in the area of the MDO osteotomies. Such injuries include distalization and/or morphologic anomalies of primary and permanent molars. We describe a case of an unusual macrodontia of the primary mandibular left second molar in a six-year-old male who underwent MDO as an infant. We believe that the mesial-distal elongation of the crown of the primary second molar occurred through distraction histogenesis of the tooth structures during the distraction of the mandible. We discuss the importance of preoperative planning to minimize such damages to the developing dentition.

Simplification of intradermal skin testing in Hymenoptera venom allergic children

BACKGROUND

The direct comparison between children and adults with Hymenoptera venom anaphylaxis (HVA) has never been extensively reported. Severe HVA with IgE-documented mechanism is the recommendation for venom immunotherapy, regardless of age.

OBJECTIVE

To determine the differences in the basic diagnostic profile between children and adults with severe HVA and its practical implications.

METHODS

We reviewed the medical records of 91 children and 121 adults.

RESULTS

Bee venom allergy was exposure dependent, regardless of age (P < .001). Atopy was more common in children (P = .01), whereas cardiovascular comorbidities were present almost exclusively in adults (P = .001). In the bee venom allergic group, specific IgE levels were significantly higher in children (29.5 kU_A/L; interquartile range, 11.30-66.30 kU_A/L) compared with adults (5.10 kU_A/L; interquartile range, 2.03-8.30 kU_A/L) (P < .001). Specific IgE levels for culprit insect venom were higher in bee venom allergic children compared with the wasp venom allergic children (P < .001). In adults, intradermal tests revealed higher sensitivity, accompanied by larger area of skin reactions, regardless of type of venom. At concentrations lower than 0.1 μg/mL, 16% of wasp venom allergic children and 39% of bee venom allergic children had positive intradermal test results. The median tryptase level was significantly higher in adults than in children for the entire study group (P = .002), as well as in bee (P = .002) and wasp venom allergic groups (P = .049).

CONCLUSION

The basic diagnostic profile in severe HVA reactors is age dependent. Lower skin test reactivity to culprit venom in children may have practical application in starting the intradermal test procedure with higher venom concentrations.

Pierre Robin Sequence: A Rare Presentation Of Absent Femur And Inguinal Hernia

Pierre Robin Sequence is a well-recognized case of rarity which presents with a triad of glossoptosis, cleft palate. We report a rare case of Pierre robin Sequence in an Asian child, with the absence of left femur and right sided inguinal hernia.

Airway and feeding problems in infants with Fairbairn-Robin triad deformities

BACKGROUND

The majority of patients with Pierre Robin sequence in the subdivision Fairbairn- Robin triad (FRT), are born with glossoptosis, retro-/micrognathia and cleft or agenesis of the palate leading to feeding difficulties and airway obstruction. There is limited literature on these problems, and on methods used to address them.

OBJECTIVES

Community nurses in the Facial Cleft Deformity Clinic evaluate associated airway obstruction and feeding problems and devise nursing interactions to address these. This retrospective study examined the incidence of airway and feeding difficulties in the neonatal, pre-surgical period, as well as the surgical and nutritional management of these infants.

METHOD

Retrospective records of 215 infants with FRT were examined and data on incidence, airway and feeding difficulties and surgical and nutritional management was collected. Descriptive statistics, including average and percentage values, were compiled.

RESULTS

The incidence of FRT amongst the cleft palate patients was 6.0%, with 37.7% of these having feeding difficulties. However, surgical interventions such as glossopexy (5.6%), distraction osteogenesis (0.9%) and tracheotomy (2.3%) for airway management were seldom required. Most of the infants who had upper airway obstruction and feeding problems were handled by means of suction and drinking plates, along with additional specific feeding aids. This reduced airway obstruction in 70.6%, and feeding problems in 62.4% of these infants.

CONCLUSION

Based on this study’s finding the introduction of the suction and drinking plate and the use of specific types of feeding devices and surgical management can improve growth and development in infants with FRT.

[Assessment and management of difficult airways in neonates with Pierre Robin sequence]

OBJECTIVE

To assess the difficult airways preoperatively in neonates with Pierre Robin sequence (PRS).

METHODS

A total of 18 newborn PRS with difficult intubation were evaluated with the assessment grade. The scores were based upon clinical observation, weight gain, airway obstruction and Cormack-Lehane classification.

RESULTS

A total of 14 neonates (77%) had medium (n = 8) and severe (n = 6) airway obstruction. And 89% (n = 16) failed to display glottis and unsuccessful tracheal intubation (50%).

CONCLUSION

The assessment practice of clinical observation, weight gain, airway obstruction and Cormack-Lehane classification may help to identify the difficult airways in neonates with PRS.

[Brainstem dysgenesis: Möbius, Cogan and Pierre Robin syndromes revisited]

We propose the term brainstem dysgenesis to designate patients with congenital dysfunction of the cranial nerves and muscle tone due to prenatal lesions or anomalies of the brainstem. In some patients, the dysgenesis is genetically determined and can be isolated or form part of a more extensive polymalformation syndrome (mutations of organizing or regulatory genes). In most patients with brainstem dysgenesis, however, the disorder is caused by prenatal destructive or disruptive lesions of vascular origin. Depending on the vessels involved and the magnitude of the lesion, clinical manifestations can range from intrauterine death to mild involvement of several cranial nerves. Clinical findings in some of these patients may coincide with those described in Möbius, Pierre Robin or Cogan syndromes and, if that is the case, the eponym will indicate the location of the brainstem lesion. Clinical manifestations in most patients with brainstem dysgenesis, however, do not fit into any of the aforementioned syndromes. In these circumstances the term brainstem dysgenesis should be used followed by a detailed description of each patient's clinical findings and/or the brainstem segment presumably involved. The prognosis of patients with brainstem dysgenesis due to prenatal destructive lesions depends on the magnitude of the vascular territory involved and, in most cases, is better than the initial clinical manifestations would indicate.

[General anesthesia outside the operating room in patients with Pierre-Robin syndrome]

Anesthesiologists are increasingly asked to involve in administering general anesthesia outside the operating room for such procedures as computed tomography, magnetic resonance imaging or angiography. Especially, pediatric patients require some kind of sedation or general anesthesia during these procedures. We report general anesthesia outside the operating room in patients with Pierre-Robin syndrome, who are expected to have possible difficult airway. A one-year-old girl and a 16-year-old boy were anesthetized for cardiac catheterization. General anesthesia was given at the angiography room which was located outside the operating room. Anesthesia was induced with oxygen, nitrous oxide and sevoflurane while portable storage unit for difficult airway was prepared including various types and size of laryngoscopes, laryngeal mask airway, fiberoptic intubation equipment and surgical airway access. Fortunately, tracheas were successfully intubated without using special devices, although cautious care during induction was taken. According to development of medical and surgical procedures, it is readily presumed that anesthesiologists will be more often involved in the sedation or anesthesia conducted outside the operating room in future. Anesthesiologists should always ensure enough staffing, proper monitoring and equipment when sedation or anesthesia is conducted outside the operating room, particularly if patients have anesthetic risks.