Evaluation of oral manifestations of patients with mucopolysaccharidosis IV and VI: clinical and imaging study

Candidate genes for obstructive sleep apnea in non-syndromic children with craniofacial dysmorphisms - a narrative review

Pediatric obstructive sleep apnea (POSA) is a complex disease with multifactorial etiopathogenesis. The presence of craniofacial dysmorphisms influencing the patency of the upper airway is considered a risk factor for POSA development. The craniofacial features associated with sleep-related breathing disorders (SRBD) - craniosynostosis, retrognathia and micrognathia, midface and maxillary hypoplasia - have high heritability and, in a less severe form, could be also found in non-syndromic children suffering from POSA. As genetic factors play a role in both POSA and craniofacial dysmorphisms, we hypothesize that some genes associated with specific craniofacial features that are involved in the development of the orofacial area may be also considered candidate genes for POSA. The genetic background of POSA in children is less explored than in adults; so far, only one genome-wide association study for POSA has been conducted; however, children with craniofacial disorders were excluded from that study. In this narrative review, we discuss syndromes that are commonly associated with severe craniofacial dysmorphisms and a high prevalence of sleep-related breathing disorders (SRBD), including POSA. We also summarized information about their genetic background and based on this, proposed 30 candidate genes for POSA affecting craniofacial development that may play a role in children with syndromes, and identified seven of these genes that were previously associated with craniofacial features risky for POSA development in non-syndromic children. The evidence-based approach supports the proposition that variants of these candidate genes could lead to POSA phenotype even in these children, and, thus, should be considered in future research in the general pediatric population.

A pictorial review of the radiographic skeletal findings in Morquio syndrome (mucopolysaccharidosis type IV)

Morquio syndrome, also known as Morquio-Brailsford syndrome or mucopolysaccharidosis type IV (MPS IV), is a subgroup of mucopolysaccharidosis. It is an autosomal recessive lysosomal storage disorder. Two subtypes of Morquio syndrome have been identified. In MPS IVA, a deficiency in N-acetylgalactosamine-6-sulfate sulfatase interrupts the normal metabolic pathway of degrading glycosaminoglycans. Accumulated undigested glycosaminoglycans in the tissue and bones result in complications leading to severe skeletal deformity. In MPS IVB, a deficiency in beta-galactosidase results in a milder phenotype than in MPS IVA. Morquio syndrome presents a variety of clinical manifestations in a spectrum of mild to severe. It classically has been considered a skeletal dysplasia with significant skeletal involvement. However, the extraskeletal features can also provide valuable information to guide further work-up to assess the possibility of the disorder. Although the disease involves almost all parts of the body, it most commonly affects the axial skeleton, specifically the vertebrae. The characteristic radiologic findings in MPS IV, such as paddle-shaped ribs, odontoid hypoplasia, vertebral deformity, metaphyseal and epiphyseal bone dysplasia, and steep acetabula, are encompassed in the term "dysostosis multiplex," which is a common feature among other types of MPS and storage disorders. Myelopathy due to spinal cord compression and respiratory airway obstruction are the most critical complications related to mortality and morbidity. The variety of clinical features, as well as overlapping of radiological findings with other disorders, make diagnosis challenging, and delays in diagnosis and treatment may lead to critical complications. Timely imaging and radiologic expertise are important components for diagnosis. Gene therapies may provide robust treatment, particularly if genetic variations can be screened in utero.

Facial and Cephalometric Features of Individuals With Mucopolysaccharidosis: A Cross-Sectional Study

OBJECTIVE

The aim was to assess craniofacial features through facial anthropometric and lateral cephalometry measurements of individuals with mucopolysaccharidosis (MPS) and compare them with individuals without MPS.

DESIGN

Cross-sectional study.

PATIENTS

A total of 14 individuals with MPS and 28 non-MPS age- and sex-matched were enrolled in this study.

METHODS

A clinical facial analysis to evaluate the soft tissues and cephalometric analysis that comprised linear and angular measurements were performed. The calculation of the method error suggested no systematic errors (p > .05). Random errors for linear and angular measurements were low (less than 0.5° and 1.6 mm). Chi-square test and independent t-test were performed.

RESULTS

Most individuals with MPS were dolichofacial, presented altered facial proportions with an increased anterior lower facial height (ALFH) and lip incompetence (all p < .05), when compared with non-MPS individuals. Six angular measurements (1s.Na, 1s.NB, FMA, IMPA, AFI, and Po.Or_Go.Me; all p < .05) were significantly increased among individuals with MPS, and two (1s.1i and Ba.N-Ptm.Gn, all p < .05) were significantly decreased among them. Four linear measurements were significantly increased among individuals with MPS (1s-NA, 1i-NB, S-UL, and S-LL; all p < .05) and five (PogN-Perp, Co-A, Co-Gn, Nfa-Nfp, and overbite; all p < .05) were significantly decreased among them.

CONCLUSION

In summary, most individuals with MPS were dolichofacial with increased ALFH. Proclined upper and lower incisors, reduced nasopharyngeal space, and reduced overbite was also noted.

Orofacial abnormalities in mucopolysaccharidosis and mucolipidosis type II and III : A systematic review

Mucopolysaccharidoses (MPSs) and mucolipidosis II and III (ML II and III) often manifest with orofacial (progressive) abnormalities, which may have a major impact on quality of life. However, because these patients have multiple somatic health issues, orofacial problems are easily overlooked in clinical practice and available literature on this topic solely consists of case reports, small case series, and small cohort studies. The aim of this systematic review was to gain more insight in the nature and extent of orofacial abnormalities in MPS, ML II, and III. A systematic review of all previously published articles addressing orofacial abnormalities in MPS, ML II, and III was performed. Both clinical studies and case reports were included. Outcome was the described orofacial abnormalities, subdivided into abnormalities of the face, maxilla, mandible, soft tissues, teeth, and occlusion. The search resulted in 57 articles, describing orofacial features in 340 patients. Orofacial abnormalities were present in all subtypes of MPS, ML II, and III, and consisted of thickened lips, a hypoplastic midface, a high‐arched palate, hypoplastic condyles, coronoid hyperplasia, macroglossia, gingival hyperplasia, thick dental follicles, dentigerous cysts, misshapen teeth, enamel defects, and open bite. Orofacial abnormalities are present in all subtypes of MPS, ML II, and III. As orofacial abnormalities may cause complaints, evaluation of orofacial health should be part of routine clinical care.

Early enzyme replacement therapy prevents dental and craniofacial abnormalities in a mouse model of mucopolysaccharidosis type VI

Mucopolysaccharidosis VI (MPS VI) is a hereditary lysosomal storage disease caused by the absence of the enzyme arylsulfatase B (ARSB). Craniofacial defects are common in MPS VI patients and manifest as abnormalities of the facial bones, teeth, and temporomandibular joints. Although enzyme replacement therapy (ERT) is the treatment of choice for MPS VI, the effects on the craniofacial and dental structures are still poorly understood. In this study, we used an Arsb-deficient mouse model (Arsbm/m) that mimics MPS VI to investigate the effects of ERT on dental and craniofacial structures and compared these results with clinical and radiological observations from three MPS VI patients. Using micro-computed tomography, we found that the craniofacial phenotype of the Arsbm/m mice was characterized by bone exostoses at the insertion points of the masseter muscles and an overall increased volume of the jaw bone. An early start of ERT (at 4 weeks of age for 20 weeks) resulted in a moderate improvement of these jaw anomalies, while a late start of ERT (at 12 weeks of age for 12 weeks) showed no effect on the craniofacial skeleton. While teeth typically developed in Arsbm/m mice, we observed a pronounced loss of tooth-bearing alveolar bone. This alveolar bone loss, which has not been described before in MPS VI, was also observed in one of the MPS VI patients. Interestingly, only an early start of ERT led to a complete normalization of the alveolar bone in Arsbm/m mice. The temporomandibular joints in Arsbm/m mice were deformed and had a porous articular surface. Histological analysis revealed a loss of physiological cartilage layering, which was also reflected in an altered proteoglycan content in the cartilage of Arsbm/m mice. These abnormalities could only be partially corrected by an early start of ERT. In conclusion, our results show that an early start of ERT in Arsbm/m mice achieves the best therapeutic effects for tooth, bone, and temporomandibular joint development. As the MPS VI mouse model in this study resembles the clinical findings in MPS VI patients, our results suggest enzyme replacement therapy should be started as early as possible.

Dental and maxillomandibular incidental findings in panoramic radiography among individuals with mucopolysaccharidosis: a cross-sectional study

Mucopolysaccharidosis (MPS) is a group of rare and inherited metabolic disorders caused by the accumulation of macromolecule glycosaminoglycans inside lysosomes. Affected individuals may have dental and craniofacial tissue alterations, facilitating the development of several oral diseases.

OBJECTIVES

To assess, with panoramic radiographic images, the frequency of dental and maxillomandibular incidental findings among MPS individuals and compare them with non-MPS individuals.

METHODOLOGY

A cross-sectional study evaluating a sample of 14 MPS individuals and 28 non-MPS individuals aged from 5 to 26 years was carried out. They were matched for sex and age on a 2:1 proportion. Panoramic radiographs were assessed for the presence/absence of the following dental and maxillomandibular alterations: dental anomalies of number (hypodontia/dental agenesis, supernumerary teeth); anomalies of form (microdontia, macrodontia, conoid teeth, taurodontism, and root dilaceration); anomalies of position (impacted tooth, inverted tooth, tooth migration, partially bony teeth, complete bony teeth); periapical alterations (furcation lesion, circumscribed bone rarefaction); other alterations (radiolucent bone lesions, radiopaque bone lesions, radiopacity in the maxillary sinus, condylar hypoplasia). Differences between groups were tested by the Fisher's exact test and chi-square test (p<0.05).

RESULTS

For intrarater agreement, Kappa values were 0.76 to 0.85. The presence of supernumerary teeth (p=0.003); conoid teeth (p=0.009); taurodontism (p<0.001); impacted teeth (p<0.001); partial bony teeth (p=0.040); complete bony teeth (p=0.013); and root dilaceration (p=0.047) were statistically more frequent in MPS individuals compared to non-MPS individuals. Bone rarefaction/furcation lesions (p=0.032), condylar hypoplasia (p<0.001), radiolucent bone lesions (p=0.001), and dentigerous cysts (p=0.002) were also more frequent in MPS individuals.

CONCLUSION

The presence of specific oral manifestations is more common in MPS individuals than non-MPS individuals.

Mucopolysaccharidosis (MPS): Review of the literature and case series of five pediatric dental patients

Patients with MPS present with a plethora of dental manifestations, accompanying behavioral difficulties and medical comorbidities which often dictate the need for treatment in specialist centers. Prevention is therefore mandatory in this high-risk group.

Pulmonary Manifestations of Endocrine and Metabolic Diseases in Children

Advances in technology, methodology, and deep phenotyping are increasingly driving the understanding of the pathologic basis of disease. Improvements in patient identification and treatment are impacting survival. This is true in endocrinology and inborn errors of metabolism, where disease-modifying therapies are developing. Inherent to this evolution is the increasing awareness of the respiratory manifestations of these rare diseases. This review updates clinicians, stratifying diseases spirometerically; pulmonary hypertension and diseases with a predisposition to recurrent pulmonary infection are discussed. This division is artificial; many diseases have multiple pathologic effects on respiration. This review does not cover the impact of obesity.

Oral health of Brazilian individuals with mucopolyssaccaridosis

PURPOSE

This study described and compared the oral characteristics of Brazilian individuals with mucopolysaccharidosis (MPS) and without MPS.

METHODS

A cross-sectional study was performed with 29 individuals with MPS and 29 without MPS and their parents/guardians. The individuals were aged between 3 and 21 years and attended at two hospitals in Belo Horizonte, southeastern Brazil. The dental characteristics were evaluated by clinical examination of dental caries, gingivitis, malocclusion, dental anomalies and developmental defects of enamel. The parents/guardians answered a questionnaire about the sociodemographic and behavioural aspects of their children. The study was approved by the Research Ethics Committee of the Federal University of Minas Gerais.

RESULTS

The average age of the individuals was 13.9 years (± 7.2). The majority were male (58.6%), had black/brown skin (70.7%) and were from favored economic class (89.7%). Dental caries, gingivitis, malocclusion and dental anomalies were more prevalent in the MPS group (p < 0.05).

CONCLUSION

The individuals with MPS had a higher prevalence of oral diseases and dental anomalies than the group without MPS.

Oral health-related quality of life of young people with mucopolysaccharidosis: a paired cross-sectional study

The purpose of the present study was to compare the perceptions of the parents/ caregivers of young people with and without Mucopolysaccharidosis (MPS) with regards to their oral health-related quality of life (OHRQoL). A cross-sectional study was conducted with 29 individuals with MPS and 29 normotypic individuals aged three to 21 years and their parents/caregivers. All parents/caregivers of young people with MPS in follow-up at two reference hospitals in the city of Belo Horizonte, southeastern Brazil, were invited to participate in the study. Individuals without MPS were recruited from the pediatric clinics of both hospitals. Parents/caregivers answered a structured questionnaire addressing the sociodemographic characteristics, behavioral habits and medical and dental history of the children as well as the Brazilian short-form version of the Parental-Caregiver (P-CPQ). The individuals with and without MPS were examined for malocclusion, dental caries and oral hygiene by an examiner who had undergone training and calibration exercises. Mean age of the subjects was 12.1 years (± 4.2). Comparing total P-CPQ scores and scores on the oral symptoms, functional limitations and wellbeing domains, the parents/caregivers individuos with MPS reported a statistically significant greater negative impact on OS domain than their counterparts. Regarding the clinical variables, malocclusion was also associated a greater negative impact on OHRQoL of young people with MPS when compared to those of young people without MPS. Our findings show the great negative impact caused by the malocclusion of young people with MPS.

Pediatric Dental Management of an Uncommon Case of Mucopolysaccharidosis Type IV A (Morquio A Syndrome): A Case Report of a Three-Year Follow-Up

Mucopolysaccharidosis type IV A or Morquio syndrome is an uncommon inherited metabolic condition caused by the deficient intralysosomal storage of glycosaminoglycans. Diagnosis is typically based on clinical examination, skeletal radiographs, and histochemical tests in blood cells or fibroblasts. It is characterized by evident skeletal deformities, poor joint mobility, severe growth deficit, occlusal anomalies, and enamel defects. The aim of the present clinical case report is to describe the general oral management provided to a 6-year-old female patient and its corresponding evolution for more than three years.

Assessing the impact of the five senses on quality of life in mucopolysaccharidoses

Background

The mucopolysaccharidoses (MPSs) are lysosomal storage disorders associated with progressive multi-organ and skeletal abnormalities. Clinical manifestations can affect each of the five senses: hearing, vision, smell, taste, and touch.

Main body of the abstract

On 24–26 May 2018, 46 specialists with expertise in managing symptoms of MPS and experts specialized in evaluating and managing impairments in each one of the five senses gathered in Lisbon, Portugal at the “MPS & the five senses” meeting to discuss how loss of one or multiple senses can affect activities of daily living (ADL) and quality of life (QoL) in MPS patients and best practices in evaluating and managing the loss of senses in these individuals. The meeting confirmed that MPS can affect the senses considerably, but how these impairments affect ADL and overall QoL from a patient’s perspective remains unclear. A better insight may be achieved by prospectively collecting patient-reported outcome (PRO) data internationally in a standardized way, using a standard battery of tools. To identify relevant PRO tools, a systematic literature review and a selection of existing published questionnaires, focused on adults with no intellectual delay, were performed after the meeting. The search strategy identified 33 PRO tools for hearing, 30 for speech, 125 for vision, 49 for touch (including pain and upper limb function), and 15 for smell/taste. A further selection was made based on several criteria, including applicability/relevance for MPS, applicability in different countries (languages)/cultures, availability in English, ease of use, validation, and normative data, resulting in a final set of 11 tools. In addition to these sense-specific PRO tools, a general QoL tool, the EuroQol (EQ)-5D-5 L, was selected to assess overall QoL and reveal coping behaviors.

Short conclusion

MPS can affect each of the five senses, but current knowledge on the impact of sense impairments on QoL/ADL in MPS patients remains limited. Collection of data in a standardized fashion using sense-specific patient-reported outcome tools and a general QoL tool may fill the current knowledge gap.

Respiratory complications of metabolic disease in the paediatric population: A review of presentation, diagnosis and therapeutic options

Inborn errors of metabolism (IEMs) whilst individually rare, as a group constitute a field which is increasingly demands on pulmonologists. With the advent of new therapies such as enzyme replacement and gene therapy, early diagnosis and treatment of these conditions can impact on long term outcome, making their timely recognition and appropriate investigation increasingly important. Conversely, with improved treatment, survival of these patients is increasing, with the emergence of previously unknown respiratory phenotypes. It is thus important that pulmonologists are aware of and appropriately monitor and manage these complications. This review aims to highlight the respiratory manifestations which can occur. It isdivided into conditions resulting primarily in obstructive airway and lung disease, restrictive lung disease such as interstitial lung disease or pulmonary alveolar proteinosis and pulmonary hypertension, whilst acknowledging that some diseases have the potential to cause all three. The review focuses on general phenotypes of IEMs, their known respiratory complications and the basic metabolic investigations which should be performed where an IEM is suspected.

Molecular characterization of a large group of Mucopolysaccharidosis type IIIC patients reveals the evolutionary history of the disease

Mucopolysaccharidosis type IIIC (MPSIIIC) is a severe, rare autosomal recessive disorder caused by variants in the heparan-α-glucosaminide N-acetyltransferase (HGSNAT) gene which result in lysosomal accumulation of heparan sulfate. We analyzed clinical presentation, molecular defects and their haplotype context in 78 (27 novel) MPSIIIC cases from 22 countries, the largest group studied so far. We describe for the first time disease-causing variants in the patients from Brazil, Algeria, Azerbaijan, and Iran, and extend their spectrum within Canada, Colombia, Turkey, and the USA. Six variants are novel: two missense, c.773A>T/p.N258I and c.1267G>T/p.G423W, a nonsense c.164T>A/p.L55*, a splice-site mutation c.494-1G>A/p.[P165_L187delinsQSCYVTQAGVRWHHLGSLQALPPGFTPFSYLSLLSSWNC,P165fs], a deletion c.1348delG/p.(D450fs) and an insertion c.1479dupA/p.(Leu494fs). The missense HGSNAT variants lacked lysosomal targeting, enzymatic activity, and likely the correct folding. The haplotype analysis identified founder mutations, p.N258I, c.525dupT, and p.L55* in the Brazilian state of Paraiba, c.493+1G>A in Eastern Canada/Quebec, p.A489E in the USA, p.R384* in Poland, p.R344C and p.S518F in the Netherlands and suggested that variants c.525dupT, c.372-2G>A, and c.234+1G>A present in cis with c.564-98T>C and c.710C>A rare single-nucleotide polymorphisms, have been introduced by Portuguese settlers in Brazil. Altogether, our results provide insights into the origin, migration roots and founder effects of HGSNAT disease-causing variants, and reveal the evolutionary history of MPSIIIC.

Mutational analysis of ARSB gene in mucopolysaccharidosis type VI: identification of three novel mutations in Iranian patients

Objective(s):

Mucopolysaccharidosis VI (MPS VI) or Maroteaux-Lamy syndrome is a rare metabolic disorder, resulting from the deficient activity of the lysosomal enzyme arylsulfatase B (ARSB). The enzymatic defect of ARSB leads to progressive lysosomal storage disorder and accumulation of glycosaminoglycan (GAG) dermatan sulfate (DS), which causes harmful effects on various organs and tissues and short stature. To date, more than 160 different mutations have been reported in the ARSB gene.

Materials and Methods:

Here, we analyzed 4 Iranian and 2 Afghan patients, with dysmorphism indicating MPS VI from North-east Iran. To validate the patients’ type of MPS VI, urine mucopolysaccharide and leukocyte ARSB activity were determined. Meanwhile, genomic DNA was amplified for all 8 exons and flanking intron sequences of the ARSB gene to analyze the spectrum of mutations responsible for the disorder in all patients.

Results:

Abnormal excretion of DS and low leukocyte ARSB activity were observed in the urine samples of all 6 studied patients. In direct DNA sequencing, we detected four different homozygous mutations in different exons, three of which seem not to have been reported previously: p.H178N, p.H242R, and p.*534W. All three novel substitutions were found in patients with Iranian breed. We further detected the IVS5+2T>C mutation in Afghan siblings and four different homozygous polymorphisms, which have all been observed in other populations.

Conclusion:

results indicated that missense mutations were the most common mutations in the ARSB gene, most of them being distributed throughout the ARSB gene and restricted to individual families, reflecting consanguineous marriages.

Imaging of the Pediatric Temporomandibular Joint

Imaging of the temporomandibular joint in pediatric patients is a critical component in the evaluation and treatment of children with temporomandibular joint symptoms. MRI can provide detailed joint anatomy and identify inflammation, sometimes before symptom onset. Ultrasound scan is a convenient emerging modality to evaluate the joint and guide therapeutic injections. Radiography and computed tomography offer osseous detail to recognize early morphologic changes of the mandibular condyle and provide operative planning. Imaging promises to direct treatment to prevent future joint destruction and maintain function.

Three-dimensional dental and craniofacial manifestations in patients with late diagnosis of mucopolysaccharidosis type II: report of 2 cases

The objective of this study was to report the clinical evaluation results and 3-dimensional (3-D) dental and craniofacial characteristics observed in 2 male patients with mucopolysaccharidosis type II. The patients were evaluated clinically (soft tissue evaluation, evaluation of occlusion, periodontal and dental examinations) and by using craniofacial computed tomography, with evaluation of 3-D images in ITK-Snap v. 2.2 (Penn Image Computing and Science Laboratory, Philadelphia, PA; http://www.itksnap.org/) and 3-D Slicer (http://www.slicer.org/) software. Mandibular 3-D volumetric label maps were built from computed tomography scans of both patients and compared through superimposition on a healthy patient's mandibular images. Clinically, the patients presented the following oral manifestations: macroglossia, total open bite and generalized diastemas, and absence of caries. Patient 1 showed dental calculus and bleeding at the gingival margin. Patient 2 showed bleeding at the gingival margin, a permanent maxillary left central incisor missing as a result of trauma, and impacted permanent mandibular left and right second molars. 3-D images showed wide arches, prominent antegonial notches, a narrow mandibular body in the region of the antegonial notches, bilateral severe condylar hypoplasia, and enlarged coronoid processes. 3-D imaging and superimpositions revealed oral and skeletal displacements, contributing to the identification of changes in the course of mucopolysaccharidosis type II in patients with a late diagnosis.