Genetic Mutations Associated with Pierre Robin Syndrome/Sequence: A Systematic Review

Airway management in infants with Robin sequence in the United Kingdom and Ireland: A prospective population-based study

OBJECTIVE

There is currently no consensus about managing upper airway obstruction (UAO) in infants with Robin sequence (RS), in terms of treatment efficacy or clinical outcomes. This study describes UAO management in UK/Ireland, and explores relationships between patient characteristics, UAO management, and clinical outcomes in the first 2 years of life.

METHODS

Active surveillance of RS throughout UK/Ireland via the British Paediatric Surveillance Unit and nationally commissioned cleft services. Clinical data were collected at initial notification and 12-month follow-up.

RESULTS

173 infants with RS were identified, of which 47% had additional congenital anomalies or an underlying syndrome (non-isolated RS). Two-thirds (n = 119) required an airway intervention other than prone positioning: non-surgical in 84% and surgical (tracheostomy) in 16%. Nasopharyngeal airway (NPA) was the most common intervention, used in 83% (n = 99) for median 90 days (IQR 136). Surgical UAO management was associated with prolonged hospital admission, higher prevalence of neurodevelopmental delay (NDD), lower weight-for-age z-scores, and delayed oral feeding. These findings were not attributable to a higher prevalence of non-isolated RS in this group. Although more commonly associated with non-isolated RS, growth faltering was also identified in 48%, and NDD in 18%, of cases of isolated RS.

CONCLUSIONS

In UK/Ireland, most infants with RS are managed with NPA, and tracheostomy is reserved for refractory severe UAO. Clinical outcomes and duration of use indicate that NPA is a safe and feasible first-line approach to UAO. Longitudinal assessment of neurodevelopment and growth is imperative, including in children with isolated RS. Current variations in practice reinforce the need for evidence-based treatment guidelines.

Postoperative respiratory difficulties following primary cleft palate repair in infants with Robin sequence versus isolated cleft palate: A retrospective study

The study aimed to: (1) compare the occurrence of postoperative respiratory difficulties (PRD) following primary cleft palate repair (CPR) in infants with an isolated cleft palate (iCP) and infants with Robin sequence (RS), and (2) describe the possible benefit of preoperative analysis with palatal plate in infants with RS. All consecutive infants with an iCP and infants with RS who underwent CPR between January 2009 and June 2022 in the Wilhelmina Children's Hospital were retrospectively reviewed. A total of 127 infants were included of which 74 infants with an iCP and 53 infants with RS. The group of infants with RS consisted of 35 infants with non-isolated RS (niRS) and 18 infants with isolated RS (iRS). Significant more PRD were seen in infants with RS compared to infants with an iCP (14/53 versus 9/74; p = 0.04). Especially infants with niRS have a significant higher risk of developing PRD in comparison with infants with an iCP (OR = 4.16, 95% CI [1.17-15.99], p = 0.031). The preoperative palatal plate screening in infants with RS (n = 25) did not show abnormalities and had no effect on the perioperative policy. Within the limitations of this study it seems that infants with niRS are more prone to develop PRD following primary CPR when compared to infants with iRS or an iCP. No clear benefit was found in postponing surgery until 12 months or later in infants with RS to avoid PRD. The preoperative palatal plate screening did not demonstrate signs of UAO in infants with RS that developed PRD. These findings suggest that preoperative analysis with palatal plate has a low predictive value.

A Newborn with Extremely Rare Cerebro-Costo-Mandibular Syndrome; A Case Report Study

BACKGROUND

Cerebro-costo-mandibular syndrome (CCMS) is a rare congenital syndrome consisting of the main features of micrognathia and posterior rib gaps. Due to multiple abnormalities, patients almost have difficulty breathing with upper airway obstruction, decreased thoracic capacity, spina bifida, and scoliosis.

CASE PRESENTATION

We describe a case of a late preterm neonate boy presenting with low Apgar, respiratory distress, and complicated orofacial anomalies that had a poor outcome. His radiographic findings showed mandibular hypoplasia (micrognathia), chest deformity, multiple posterior rib gap defects, and abnormal costotransverse articulation. Based on physical examination and radiologic findings, the diagnosis of CCMS confirmed for the patient.

CONCLUSION

Physicians should always consider the diagnosis of CCMS in all infants with micrognathia and rib-gap defects. These infants need careful respiratory function monitoring. Early airway management improves growth and development. In addition, their physical and psychological development should be assessed regularly.

Prospective cohort study on facial profile changes in infants with Robin sequence and healthy controls

BACKGROUND

Various conservative and surgical approaches exist to treat Robin sequence (RS), but their effects on facial profile and mandibular catch-up growth are unclear. A functional treatment concept, used in our centre for 25 years, includes an individualized palatal plate with a velo-pharyngeal extension and intensive feeding training.

METHODS

We performed a prospective study to objectively describe facial profiles in infants with RS treated with the above concept. Infants with isolated RS were admitted to our tertiary perinatal and national referral centre for craniofacial malformations between May 2018 and Nov 2019. Infants with RS received 3D-photographs during clinically indicated visits. Healthy controls were recruited from Dec 2018 to Sep 2019 and received 3D-photographs every 3 months. The digitally measured jaw index (JI), defined as alveolar overjet (O) x maxillary arch (U)/mandibular arch (L), and the soft tissue reference points A'-point, Nasion', B'-point angle (ANB'), describing the relative position of maxilla to mandible, were evaluated. Linear mixed models were used to examine time trajectories in JI and ANB'.

RESULTS

A total of 207 3D images, obtained in 19 infants with RS and 32 controls, were analysed. JI and ANB' decreased over time in both groups [for JI - 0.18 (95% CI - 0.25 to - 0.10); for ANB': - 0.40° per month [(95% CI - 0.48 to - 0.32)]] but remained lower in controls [for JI - 2.5 (95% CI - 3.2 to - 1.8); for ANB'-1.7° (95% CI - 2.4 to - 1.0)]. Also, the ANB' model showed a significant effect of the interaction term diagnosis x age.

CONCLUSIONS

Based on longitudinal 3D images, we describe changes in objective parameters of facial profile in infants with and without RS during the first year of life. Our findings indicate catch-up growth in infants treated for RS. Video Abstract.

Clinical and Genetic Correlation in Neurocristopathies: Bridging a Precision Medicine Gap

Neurocristopathies (NCPs) encompass a spectrum of disorders arising from issues during the formation and migration of neural crest cells (NCCs). NCCs undergo epithelial-mesenchymal transition (EMT) and upon key developmental gene deregulation, fetuses and neonates are prone to exhibit diverse manifestations depending on the affected area. These conditions are generally rare and often have a genetic basis, with many following Mendelian inheritance patterns, thus making them perfect candidates for precision medicine. Examples include cranial NCPs, like Goldenhar syndrome and Axenfeld-Rieger syndrome; cardiac-vagal NCPs, such as DiGeorge syndrome; truncal NCPs, like congenital central hypoventilation syndrome and Waardenburg syndrome; and enteric NCPs, such as Hirschsprung disease. Additionally, NCCs' migratory and differentiating nature makes their derivatives prone to tumors, with various cancer types categorized based on their NCC origin. Representative examples include schwannomas and pheochromocytomas. This review summarizes current knowledge of diseases arising from defects in NCCs' specification and highlights the potential of precision medicine to remedy a clinical phenotype by targeting the genotype, particularly important given that those affected are primarily infants and young children.

Pierre Robin sequence coexisting with ectopic kidney, bilateral developmental hip dysplasia in a child - A rare case report

Pierre Robin sequence is a rare congenital disorder with variable associations. A two-year-old female child was brought in with complaints of an abnormal gait and right lower limb shortening. A comprehensive clinical evaluation unveiled facial characteristics resembling those of Pierre Robin Sequence, including micrognathia, a cleft palate, and glossoptosis. The child also exhibited retrognathia, a low posterior hairline, bilateral developmental dysplasia of the hips, right foot syndactyly, and a left ectopic kidney as confirmed by ultrasonography. Radiological examination showed bilateral developmental dysplastic hips. The connection between Pierre Robin sequence and the presence of bilateral dysplastic hips and an ectopic kidney is an unusual and rare combination.

Analysis of the cause of retrolingual obstruction in patients with moderate-severe obstructive sleep apnea

PURPOSE

To evaluate the percentage of obstructive sleep apnea (OSA) patients with retrolingual obstruction in all moderate-severe OSA patients and the proportions of different causes in all moderate-severe OSA patients with retrolingual obstruction and to discuss the accuracy of the Friedman tongue position (FTP) and retrolingual cross-sectional area (RCSA) in assessing the retrolingual obstruction.

METHODS

Two hundred and twenty moderate-severe OSA patients were enrolled. After retrolingual obstruction was diagnosed, the percentage of OSA patients with retrolingual obstruction in all moderate-severe OSA patients was calculated. After that, the different causes of retrolingual obstruction were diagnosed based on different diagnostic criteria, and the proportions of different causes in all moderate-severe OSA patients with retrolingual obstruction were calculated. Finally, the correlations between FTP, RCSA, and apnea-hypopnea index after nasopharyngeal tube insertion (NPT-AHI) were analyzed, and the proportions of different causes of retrolingual obstruction based on different FTP and RCSA were observed.

RESULTS

There were 128 patients with retrolingual obstruction, accounting for 58.2% of all moderate-severe OSA patients. In 128 patients with retrolingual obstruction, the proportions of glossoptosis (48.4%), palatal tonsil hypertrophy (28.1%), and lingual hypertrophy (8.6%) were relatively high. Both FTP and RCSA did not correlate with NPT-AHI. The proportion of lingual hypertrophy increased gradually with the increase of FTP and the proportions of glossoptosis in all FTP classifications were high. The patients with RCSA > 180 mm2 were mainly affected by glossoptosis and palatal tonsil hypertrophy, while patients with RCSA ≤ 180 mm2 were mainly affected by lingual hypertrophy.

CONCLUSION

The percentage of patients with retrolingual obstruction in all moderate-severe OSA patients is relatively high, mainly glossoptosis, palatal tonsil hypertrophy, and lingual hypertrophy. FTP classification and RCSA can only reflect the retrolingual anatomical stenosis, but cannot fully reflect the retrolingual functional stenosis, especially the presence of glossoptosis.

Global birth prevalence of Robin sequence in live-born infants: a systematic review and meta-analysis

Robin sequence (RS), a congenital disorder of jaw maldevelopment and glossoptosis, poses a substantial healthcare burden and has long-term health implications if airway obstruction is suboptimally treated. This study describes the global birth prevalence of RS and investigates whether prevalence estimates differ by geographical location, ethnicity or study data source (registry versus non-registry data). The protocol was prospectively registered with PROSPERO.Databases were searched using keywords and subject terms for "Robin sequence", "epidemiology", "incidence" and "birth prevalence". Meta-analysis was performed fitting random effects models with arcsine transformation.From 34 eligible studies (n=2722 RS cases), pooled birth prevalence was 9.5 per 100 000 live births (95% CI 7.1-12.1) with statistical heterogeneity. One third of studies provided a case definition for RS and numerous definitions were used. A total of 22 countries were represented, predominantly from European populations (53% of studies). There was a trend towards higher birth prevalence in European populations and lower prevalence from registry-based studies. Only two studies reported ethnicity.This study indicates that RS occurs globally. To investigate geographical differences in prevalence, additional studies from non-European populations and reporting of ethnicity are needed. Heterogeneity of estimates may be due to variable diagnostic criteria and ascertainment methods. Recently published consensus diagnostic criteria may reduce heterogeneity among future studies.

Developmental outcome of children with Robin sequence treated with the current Paris protocol

AIM

We aimed to investigate the developmental outcome of children with Robin sequence (RS) for whom continuous positive airway pressure was the main strategy to release upper airway obstruction.

METHODS

We included children with isolated RS or RS associated with Stickler syndrome who were aged 15 months to 6 years. We used the French version of the Child Development Inventory and calculated the developmental quotient (DQ) for eight different domains and the global DQ (DQ-global). We searched for determinants of risk of delay.

RESULTS

Of the 87 children, for 71%, the developmental evolution was within the norm (DQ-global ≥86 or ≥-1 SD), 29% were at high risk of delay (DQ-global <86 or <-1 SD), and only 3% were at very high risk of delay (DQ-global <70 or <-2 SD). The DQs for expressive language and language comprehension were lower in our study population than the general population, but an improvement was noticed with the children's growth.

CONCLUSION

Risk of a developmental delay was not greater for children with the most severe respiratory phenotype than the others. Children whose mothers had low education levels were more at risk than the others.

Prevalence and Management of Laryngomalacia in Patients With Pierre Robin Sequence

OBJECTIVE

To characterize the prevalence and presentation of laryngomalacia and efficacy of supraglottoplasty (SGP) in a cohort of patients with Pierre Robin Sequence (PRS).

DESIGN

Retrospective cohort study.

SETTING

Tertiary-care children's hospital.

PATIENTS, PARTICIPANTS

Consecutive patients with PRS born between January 2010 and June 2018.

MAIN OUTCOME MEASURES

Chart review included demographics, comorbid airway obstruction including laryngomalacia, timing of surgical interventions, clinical symptoms, sleep study data, and modified barium swallow study data.

126 patients with PRS were included; 54% had an associated syndrome, 64% had an overt cleft palate, and 22% had a submucous cleft palate. 64/126 were noted to have laryngomalacia (51%). Patients with concurrent PRS and laryngomalacia were significantly more likely to have submucous cleft palate (P = .005) and present with aspiration with cough (P = .01) compared to patients with PRS without laryngomalacia. Patients with concurrent laryngomalacia and PRS showed a significant decrease in apnea-hypopnea index (AHI) and obstructive AHI (OAHI) after mandibular distraction, with a median AHI and OAHI improvement of 22.3 (P = .001) and 19.8 (P = .002), respectively. Patients who underwent only SGP did not show significant improvement in these parameters (P = .112 for AHI, P = .064 for OAHI).

The prevalence of laryngomalacia in our PRS cohort was 51%. Patients with PRS and laryngomalacia are more likely to present with overt aspiration compared to patients with PRS without laryngomalacia. These data support that laryngomalacia does not appear to be a contraindication to pursuing MDO.

Epidemiology of Robin sequence in the UK and Ireland: an active surveillance study

BACKGROUND

Birth prevalence of Robin sequence (RS) is commonly reported as 1 case per 8000-14 000 live births. These estimates are based on single-source case ascertainment and may miss infants who did not require hospital admission or those without overt upper airway obstruction at birth.

OBJECTIVES

To identify the true birth prevalence of RS with cleft palate in the UK and Ireland from a population-based birth cohort with high case ascertainment.

METHODS

Active surveillance of RS with cleft palate was carried out in the UK/Ireland using dual sources of case ascertainment: British Paediatric Surveillance Unit (BPSU) reporting card and nationally commissioned cleft services. Clinical data were collected from notifying clinicians at two time points.

RESULTS

173 live-born infants met the surveillance case definition, giving a birth prevalence of 1 case per 5250 live births (19.1 per 100 000 (95% CI 16.2 to 21.9)), and 1:2690 in Scotland. 47% had non-isolated RS, with Stickler syndrome the most common genetic diagnosis (12% RS cases). Birth prevalence derived from the combined data sources was significantly higher than from BPSU surveillance alone.

CONCLUSIONS

Birth prevalence of RS in the UK/Ireland derived from active surveillance is higher than reported by epidemiological studies from several other countries, and from UK-based anomaly registries, but consistent with published retrospective data from Scotland. Dual case ascertainment sources enabled identification of cases with mild or late-onset airway obstruction that were managed without hospital admission. Studies of aetiology and equivalent well-designed epidemiological studies from other populations are needed to investigate the identified geographical variability in birth prevalence.

Genetics and orofacial clefts: a clinical perspective

Orofacial clefts (OFCs) are the most common congenital craniofacial anomaly seen in humans. Most OFCs are sporadic and isolated - these are thought to be multifactorial in origin. Chromosomal and monogenic variants account for the syndromic forms and for some of the non-syndromic inherited forms. This review discusses the importance of genetic testing and the current clinical strategy to deliver a genomics service that is of direct benefit to patients and their families.

The Pathogenesis of Pierre Robin Sequence through a Review of SOX9 and Its Interactions

The literature does not offer any review of the pathogenesis of the clinical features of syndromes with Pierre Robin sequence (PRS). The senior author (MMA) proposed a hypothesis that SOX9 and its interactions may play a key role in this pathogenesis. The current review aims to test this hypothesis.

Treated Pierre Robin Sequence Using Placed Allogenic Acellular Bone Matrix and Mandibular Distraction Osteogenesis in the Neonate

OBJECTIVE

The aim of the study was to report our experience with placed allogenic acellular bone matrix and mandibular distraction osteogenesis in Pierre Robin sequence (PRS), and explore the role of distraction in the osteogenesis of acellular bone.

MATERIALS AND METHODS

A total of 428 neonates with severe PRS managed with placing allogenic acellular bone and bilateral mandibular distraction osteogenesis were included in the study. The procedure included using oblique-shaped osteotomy, fixing bilateral mandibular distractor, instantly extending a 4-6 mm gap, and placing allogenic acellular bone into the gap. The length of allogenic acellular bone was 4-5 mm. Although the surgical techniques, distraction, and consolidation periods were similar, the allogenic acellular bone matrix we placed was quite different from the traditional distraction. With the technology we used, tracheal intubation could be immediately removed, thus quickly improving breathing conditions compared to traditional methods after the surgery. The jaw extending and oral feeding could begin on the 5th day. The jaw was extended 0.6 mm twice a day until the mandible was overcorrected by 20%.

RESULTS

All 428 cases included in this study were successfully extubated after the operation, and the difficulty in breathing was instantly relieved. Total mandibular distraction was 15-20 mm. Oral feeding was started at 6 h to 6 days postoperatively, while hospital stay ranged from 18 to 20 days postoperatively. No major complications were reported. Medium to long-term results was good. Mandibular distractors were removed after 3 months.

CONCLUSIONS

Bilateral mandibular distraction osteogenesis combined with placing allogenic acellular bone in the neonate are safe and accurate procedures, which are the primary treatment options for cases of severe PRS. It can be considered that the tension of distraction can promote osteogenesis in acellular bone and thus improve distractive effect of the mandible.

Developmental outcome of children with Robin sequence: How does the question arise?

Robin sequence (RS) is a heterogeneous congenital condition characterized by retrognathia, glossoptosis, upper airway obstruction, and very often, posterior U-shape cleft palate. Half the children with RS have an underlying syndrome, either identified (syndromic RS) or not (RS+). Long-term intellectual developmental outcome first depends on the underlying diagnosis and is often poor in syndromic cases. On the contrary, the rare studies that analysed the long-term developmental outcome of children with isolated RS who received effective treatment of their respiratory and feeding difficulties early in life, showed intellectual and academic results close to or within the normal range. Speech outcome in RS is often delayed with phonation disorders. Speech difficulties depend on intellectual level, hearing and velar function after palate repair. It affects most children with RS and deserves active monitoring and care.

Next Generation Sequencing and Cytogenetic Based Evaluation of Indian Pierre Robin Sequence Families Reveals CNV Regions of Modest Effect and a Novel LOXL3 Mutation

BACKGROUND

Pierre Robin Sequence (PRS) affects approximately 1 per 8500 to 14000 new-borns worldwide. Although the clinical entity is well defined, the pathogenesis of PRS is debated. The present study aims to understand the contribution of genomic imbalances and genetic variants in patients clinically diagnosed of PRS.

METHODOLOGY

A total of 7 independent patients with nonsyndromic PRS thoroughly evaluated by a medical geneticist at a tertiary care hospital, were included in the study. Blood samples were collected from these patients and their family members. Array CGH was performed on all 7 patients and their respective family members for detection of underlying cytogenetic defects. Whole exome sequencing (WES) was performed for 5 families to capture single nucleotide variants or small indels.

RESULTS

Cytogenetic analyses did not detect any previously reported gross chromosomal aberrations for PRS in the patient cohort. However, copy number variations (CNVs) of size <1 Mb were detected in patients which may have implications in PRS. The present study provided evidence for the occurrence of de novo deletions at 7p14.1 locus in PRS patients: further validating the candidate loci susceptibility in oral clefts. WES data identified LOXL3 as candidate gene, carrying novel deleterious variant, which is suggestive of the role of point mutations in the pathogenesis of PRS.

CONCLUSION

The present study offered considerable insight into the contribution of cytogenetic defects and novel point mutation in the etiology of nonsyndromic PRS. Studies comprising large number of cases are required to fully elucidate the genetic mechanisms underlying the PRS phenotype.

A Visual Phenotype-Based Differential Diagnosis Process for Rare Diseases

PURPOSE

Phenotype-based rapid diagnosis can make up for the time-consuming genetic sequencing diagnosis of rare diseases. However, the collected phenotypes of patients can sometimes be inaccurate or incomplete, which limits the accuracy of diagnostic results. To solve this problem, we try to design a phenotype-based differential diagnosis process for rare diseases to achieve rapid and accurate diagnosis of rare diseases.

METHODS

The core of the differential diagnosis of rare diseases is to optimize the phenotype information of a specific patient and the visualized comparative analysis of diseases. To recommend additional phenotypes, replace the fuzzy phenotypes and filter the unexplained phenotypes for patients, we constructed a phenotype hierarchical network and a disease-phenotype differential network and calculated the phenotype co-occurrence relationship. In addition, we designed a visual comparative analysis method to explore the correlation and difference of disease phenotypes.

RESULTS

The evaluation based on the published 10 rare disease cases demonstrated that after the optimization of patient phenotype information through our differential diagnosis, the target disease often got a better ranking and recommendation score than before. We have deployed this scheme on the RDmap project ( http://rdmap.nbscn.org ).

CONCLUSION

Compared to genetic and molecular analysis, phenotype-based diagnosis is faster, cheaper, and easier. The differential diagnosis process we designed can optimize the phenotype information of patients and better locate the target disease. It can also help to make screening decisions before genetic testing.