Oligodontia in the Clinical Spectrum of Syndromes: A Systematic Review

The aim of this systematic review was to describe the clinical and genetic features of syndromes showing oligodontia as a sign. The review was performed according to the PRISMA 2020 checklist guidelines, and the search was conducted using PubMed, Scopus, Lilacs, Web of science, Livivo, and EMBASE and supplemented by a gray literature search on Google Scholar and ProQuest, applying key terms relevant to the research questions. The systematic review identified 47 types of syndromes in 83 studies, and the most common was hypohidrotic ectodermal dysplasia, which was reported in 24 patients in 22 studies. Other common syndromes that reported oligodontia included Axenfeld-Rieger syndrome, Witkop's syndrome, Ellis-van Creveld syndrome, blepharocheilodontic syndrome, and oculofaciocardiodental syndrome. The X-linked mode of inheritance was the most reported (n = 13 studies), followed by the autosomal dominant (n = 13 studies). The review describes the main syndromes that may have oligodontia as a clinical sign and reinforces the need for orodental-facial examining for adequate diagnosis and treatment of the affected patients. Molecular analysis in order to better understand the occurrence of oligodontia is imperative.

A Novel Variant in the Desmoplakin Gene in One Case of the Rare Carvajal Syndrome with Dilated Cardiomyopathy: A Case Report and Literature Review

Carvajal syndrome is a rare hereditary cardiocutaneous syndrome caused by the variants of the desmoplakin (DSP) gene. In this study, we report a patient of Carvajal syndrome with a novel homozygous missense variant of DSP gene. We diagnosed a 7-year-old female patient with Carvajal syndrome characterized by dilated cardiomyopathy, palmoplantar keratoderma, woolly hair, and dental dysplasia, who disclosed a novel homozygous missense variant c.4597C > T (p.Q1533X) in exon 6 of the DSP gene found for the first time. Both her parents were heterozygous for the identified nonsense variant c.4597C > T (p.Q1533X) in DSP gene but neither showed evidence of Carvajal syndrome, indicating that this novel variant causes the disease in an autosomal recessive manner. Genotypes of Carvajal syndrome are even broader than so far anticipated. When patients with dilated cardiomyopathy, palmoplantar keratoderma, woolly hair, and dental dysplasia are found in clinical practice, Carvajal syndrome should be highly suspected, and family gene sequencing should be actively carried out.

A new de novo heterozygous missense mutation in the desmoplakin gene, causing Naxos and Carvajal disease, associating oligodontia and nail fragility

A new de novo heterozygous mutation in the desmoplakin gene, causing Naxos and Carvajal disease, has been reported in a 13-year-old Caucasian girl, with expanded clinical phenotype. In addition to woolly hair, palmoplantar keratoderma and cardiomyopathy, she had oligodontia and nail fragility. These additional clinical features may help in the diagnosis of Naxos and Carvajal disease, known to be severe on the cardiac level.

Desmoplakin and clinical manifestations of desmoplakin cardiomyopathy

Desmoplakin (DSP), encoded by the DSP gene, is the main desmosome component and is abundant in the myocardial tissue. There are three DSP isoforms that assume the role of supporting structural stability through intercellular adhesion. It has been found that DSP regulates the transcription of adipogenic and fibrogenic genes, and maintains appropriate electrical conductivity by regulating gap junctions and ion channels. DSP is essential for normal myocardial development and the maintenance of its structural functions. Studies have suggested that DSP gene mutations are associated with a variety of hereditary cardiomyopathy, such as arrhythmia cardiomyopathy, dilated cardiomyopathy (DCM), left ventricular noncompaction, and is also closely associated with the Carvajal syndrome, Naxos disease, and erythro-keratodermia-cardiomyopathy syndrome with skin and heart damage. The structure and function of DSP, as well as the clinical manifestations of DSP-related cardiomyopathy were reviewed in this article.

Variant NAXOS-Carvajal Syndrome with Rare Additional Features of Systemic Bulla and Brittle Nails: A Case Report and Literature Review

Skin abnormalities are often indicative of cardiovascular diseases. Such a disease entity is called cardiocutaneous syndrome; however, the details regarding the involvement of bulla and nails remain largely unclear. A 49-year-old man with systemic bulla was admitted for heart failure. His bulla had previously been diagnosed as epidermolysis bullosa, but no known gene mutations for it had been identified. He had a triad of palmoplantar keratosis, curly and fine hair, and cardiomyopathy, which are characteristic of NAXOS-Carvajal syndrome. This case highlights the fact that bulla and brittle nails can accompany NAXOS-Carvajal syndrome, showing that these extra-cardiac findings can help identify otherwise overlooked serious cardiac conditions.

Arrhythmogenic Right Ventricular Cardiomyopathy in Pediatric Patients: An Important but Underrecognized Clinical Entity

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by fibrofatty infiltration of predominantly the right ventricular (RV) myocardium. Affected patients typically present as young adults with hemodynamically stable ventricular tachycardia, although pediatric cases are increasingly recognized. These young subjects often have a more severe phenotype with a high risk of sudden cardiac death (SCD) and progression toward heart failure. Diagnosis of ARVC is made by combining multiple sources of information as prescribed by the consensus-based Task Force Criteria. The description of Naxos disease, a fully penetrant autosomal recessive disorder that is associated with ARVC and a cutaneous phenotype of palmoplantar keratoderma and wooly hair facilitated the identification of the genetic cause of ARVC. At present, approximately 60% of patients are found to carry a pathogenic variant in one of five genes associated with the cardiac desmosome. The incomplete penetrance and variable expressivity of these variants however implies an important role for environmental factors, of which participation in endurance exercise is a strong risk factor. Since there currently is no definite cure for ARVC, disease management is directed toward symptom reduction, delay of disease progression, and prevention of SCD. This clinically focused review describes the spectrum of ARVC among children and adolescents, the genetic architecture underlying this disease, the cardio-cutaneous syndromes that led to its identification, and current diagnostic and therapeutic strategies in pediatric ARVC subjects.

Hair and skin predict cardiomyopathies: Carvajal and erythrokeratodermia cardiomyopathy syndromes

Carvajal and erythrokeratodermia cardiomyopathy syndromes (EKC) are rare, inherited cardiocutaneous disorders with potentially fatal consequences in young children. Some patients display features of congestive heart failure and rapidly deteriorate; others exhibit no evident warning signs until sudden death reveals underlying heart disease. We present two patients to illustrate the characteristic hair, skin, teeth, and nail abnormalities, which-especially when distinct from that of other family members-should prompt cardiac evaluation and genetic analysis. In this article, we discuss established treatments as well as a promising, novel therapeutic that has led to nearly complete resolution of the cutaneous and cardiac pathology in EKC syndrome.

Naxos disease - a narrative review

INTRODUCTION

Naxos disease is a rare entity that manifests with woolly hair, keratosis of extremities, and cardiac manifestations that resemble arrhythmogenic right ventricular cardiomyopathy. It is inherited in an autosomal recessive pattern and mutations affecting plakoglobin and desmoplakin have been identified. There is an increased risk of arrhythmias, including sudden cardiac death at a young age. Right ventricular systolic dysfunction often progresses and left ventricular involvement may also occur.

AREAS COVERED

This article reviews historic background, epidemiology, clinical characteristics, genetics, and pathogenesis as well as therapeutic management and future perspectives.

EXPERT OPINION

The principles of evaluation and treatment are based on arrhythmogenic right ventricular cardiomyopathy (ARVC) and general heart failure guidelines, because specific data on Naxos disease are limited. Therefore, larger registries on Naxos disease are welcome in order to gain more knowledge about clinical course and risk stratification. Translational research on pathophysiological mechanisms has evolved, including promising approaches using stem cells for novel targets.

Intercalated discs: cellular adhesion and signaling in heart health and diseases

Intercalated discs (ICDs) are highly orchestrated structures that connect neighboring cardiomyocytes in the heart. Three major complexes are distinguished in ICD: desmosome, adherens junction (AJ), and gap junction (GJ). Desmosomes are major cell adhesion junctions that anchor cell membrane to the intermediate filament network; AJs connect the actin cytoskeleton of adjacent cells; and gap junctions metabolically and electrically connect the cytoplasm of adjacent cardiomyocytes. All these complexes work as a single unit, the so-called area composita, interdependently rather than individually. Mutation or altered expression of ICD proteins results in various cardiac diseases, such as ARVC (arrhythmogenic right ventricular cardiomyopathy), dilated cardiomyopathy, and hypotrophy cardiomyopathy, eventually leading to heart failure. In this article, we first review the recent findings on the structural organization of ICD and their functions and then focus on the recent advances in molecular pathogenesis of the ICD-related heart diseases, which include two major areas: i) the ICD gene mutations in cardiac diseases, and ii) the involvement of ICD proteins in signal transduction pathways leading to myocardium remodeling and eventual heart failure. These major ICD-related signaling pathways include Wnt/β-catenin pathway, p38 MAPK cascade, Rho-dependent serum response factor (SRF) signaling, calcineurin/NFAT signaling, Hippo kinase cascade, etc., which are differentially regulated in pathological conditions.

Syndromes associated with dental agenesis

INTRODUCTION

Dental agenesis is the congenital absence of a variable number of teeth due to the lack of formation of the corresponding tooth germ. The aim of this work was to investigate the syndromic conditions characterized by dental agenesis.

EVIDENCE ACQUISITION

Based on the research conducted through the OMIM® (Online Mendelian Inheritance in Man) and PubMed online databases, more than ninety syndromes associated with severe or moderate agenesis have been found.

EVIDENCE SYNTHESIS

The main clinical features of these syndromes are described, especially those concerning the stomatognathic apparatus, referring to the most recent literature. Among these syndromes there are three clinical conditions associated with dental agenesis that are common for the clinician: Down Syndrome, ectodermal dysplasia and labio-palatal cleft.

CONCLUSIONS

It must be kept in mind that the success of the treatment of these patients is based on the compliance of the patient as well as on the collaboration among specialists.

Genetics of inherited cardiocutaneous syndromes: a review

The life of a human being originates as a single cell which, under the influence of certain factors, divides sequentially into multiple cells that subsequently become committed to develop and differentiate into the different structures and organs. Alterations occurring early on in the development process may lead to fetal demise in utero. Conversely, abnormalities at later stages may result in structural and/or functional abnormalities of varying severities. The cardiovascular system and skin share certain developmental and structural factors; therefore, it is not surprising to find several inherited syndromes with both cardiac and skin manifestations. Here, we will review the overlapping pathways in the development of the skin and heart, as well as the resulting syndromes. We will also highlight several cutaneous clues that may help physicians screen and uncover cardiac anomalies that may be otherwise hidden and result in sudden cardiac death.

Autosomal dominant Carvajal plus syndrome due to the novel desmoplakin mutation c.1678A > T (p.Ile560Phe)

Background

Carvajal syndrome is an autosomal dominant or autosomal recessive disorder, manifesting with dilated cardiomyopathy, woolly hair, and palmoplantar keratoma. Additional manifestations can be occasionally found. Carvajal syndrome may be due to mutations in the desmocollin-2, desmoplakin, or plakophilin-2 gene.

Methods and results

We report a family with Carvajal syndrome which additionally presented with hypoacusis, noncompaction, recurrent pharyngeal infections, oligodontia, and recurrent diarrhoea. Father and brother were also affected and had died suddenly, the father despite implantation of a cardioverter defibrillator (ICD). Genetic studies revealed the novel pathogenic mutation c.1678A > T in the desmoplakin gene resulting in the amino acid change Ile to Phe at position 560 in the index case and her brother. The index case underwent ICD implantation recently.

Conclusion

Phenotypic manifestations of Carvajal syndrome are even broader than so far anticipated, the number of mutations in the desmoplakin gene responsible for Carvajal syndrome is still increasing, and these patients require implantation of an ICD as soon as their diagnosis is established.

Dominant de novo DSP mutations cause erythrokeratodermia-cardiomyopathy syndrome

Disorders of keratinization (DOK) show marked genotypic and phenotypic heterogeneity. In most cases, disease is primarily cutaneous, and further clinical evaluation is therefore rarely pursued. We have identified subjects with a novel DOK featuring erythrokeratodermia and initially-asymptomatic, progressive, potentially fatal cardiomyopathy, a finding not previously associated with erythrokeratodermia. We show that de novo missense mutations clustered tightly within a single spectrin repeat of DSP cause this novel cardio-cutaneous disorder, which we term erythrokeratodermia-cardiomyopathy (EKC) syndrome. We demonstrate that DSP mutations in our EKC syndrome subjects affect localization of desmosomal proteins and connexin 43 in the skin, and result in desmosome aggregation, widening of intercellular spaces, and lipid secretory defects. DSP encodes desmoplakin, a primary component of desmosomes, intercellular adhesion junctions most abundant in the epidermis and heart. Though mutations in DSP are known to cause other disorders, our cohort features the unique clinical finding of severe whole-body erythrokeratodermia, with distinct effects on localization of desmosomal proteins and connexin 43. These findings add a severe, previously undescribed syndrome featuring erythrokeratodermia and cardiomyopathy to the spectrum of disease caused by mutation in DSP, and identify a specific region of the protein critical to the pathobiology of EKC syndrome and to DSP function in the heart and skin.

Two Novel Homozygous Desmoplakin Mutations in Carvajal Syndrome

BACKGROUND

Mutations in various desmosomal proteins were shown to cause inherited forms of cardiomyopathy. Carvajal syndrome (Online Mendelian Inheritance in Man [OMIM] 605676) is characterized by the association of dilated cardiomyopathy, striate palmoplantar keratoderma, and woolly hair. It is caused by homozygous as well as heterozygous mutations in DSP, which encodes the desmosomal plaque protein desmoplakin. An overlapping cardiocutaneous phenotype was also described with homozygous mutations in genes encoding two other desmosomal proteins; plakoglobin (Naxos disease; OMIM 601214) and desmocollin-2 (OMIM 610476).

METHODS

We performed clinical and molecular workups in two consanguineous Arab Palestinian families manifesting an autosomal recessive pattern of inheritance of the above mentioned clinical findings. Whole exome sequencing was employed in the search for the causing mutation.

RESULTS

Affected family members suffered from biventricular involvement and arrhythmogenic right ventricular dysplasia based on echocardiography and magnetic resonance imaging. One patient who underwent implantation of an implantable cardioverter-defibrillator (ICD) is still alive at the age of 59 years. Whole exome sequencing revealed two novel homozygous mutations in DSP, each affecting one family.

CONCLUSIONS

The association of woolly hair with palmoplantar keratoderma in a child should lead to a cardiac workup in the search for those at increased risk for sudden cardiac death. Early diagnosis and ICD implantation may be lifesaving. Whole exome sequencing should be utilized for rapid genetic analysis since the cardiocutaneous phenotype may result from mutations in one of several genes.

Desmosome regulation and signaling in disease

Desmosomes are cell-cell adhesive organelles with a well-known role in forming strong intercellular adhesion during embryogenesis and in adult tissues subject to mechanical stress, such as the heart and skin. More recently, desmosome components have also emerged as cell signaling regulators. Loss of expression or interference with the function of desmosome molecules results in diseases of the heart and skin and contributes to cancer progression. However, the underlying molecular mechanisms that result in inherited and acquired disorders remain poorly understood. To address this question, researchers are directing their studies towards determining the functions that occur inside and outside of the junctions and the extent to which functions are adhesion-dependent or independent. This review focuses on recent discoveries that provide insights into the role of desmosomes and desmosome components in cell signaling and disease; wherever possible, we address molecular functions within and outside of the adhesive structure.

Early-onset heart failure, alopecia, and cutaneous abnormalities associated with a novel compound heterozygous mutation in desmoplakin

Mutations in the desmosomal protein desmoplakin have been associated with various conditions affecting the skin and heart. The prototype is Carvajal syndrome, characterized by cardiomyopathy, woolly hair, palmoplantar keratoderma (PPK), and skin fragility. We report the case of a 3-year-old boy presenting with severe left-sided heart failure with a preceding history of cutaneous abnormalities including congenital alopecia, PPK, nail dystrophy, and follicular hyperkeratosis on the extensor surfaces. Genetic testing revealed a novel combination of two heterozygous mutations in the DSP gene encoding desmoplakin: R1400X and R2284X. Both are predicted to be deleterious to protein function. This case adds to our understanding of the spectrum of clinical presentations of syndromes associated with desmoplakin mutations and highlights the need for cardiac examination in patients with characteristic cutaneous findings.

Inherited desmosomal disorders

Desmosomes serve as intercellular junctions in various tissues including the skin and the heart where they play a crucial role in cell-cell adhesion, signalling and differentiation. The desmosomes connect the cell surface to the keratin cytoskeleton and are composed of a transmembranal part consisting mainly of desmosomal cadherins, armadillo proteins and desmoplakin, which form the intracytoplasmic desmosomal plaque. Desmosomal genodermatoses are caused by mutations in genes encoding the various desmosomal components. They are characterized by skin, hair and cardiac manifestations occurring in diverse combinations. Their classification into a separate and distinct clinical group not only recognizes their common pathogenesis and facilitates their diagnosis but might also in the future form the basis for the design of novel and targeted therapies for these occasionally life-threatening diseases.

Clinical interpretation of genetic variants in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy is an inherited cardiac entity characterized by right ventricular, or biventricular, fibrofatty replacement of myocardium. Structural alterations may lead to sudden cardiac death, mainly in young males during exercise. Autosomal dominant pattern of inheritance is reported in most parts of pathogenic genetic variations identified. Currently, 13 genes have been associated with the disease but nearly 40 % of clinically diagnosed cases remain without a genetic diagnosis. New genetic technologies allow further genetic analysis, generating a significant amount of genetic data in novel genes, which is often classified as of ambiguous significance. We focus on genetic advances of arrhythmogenic right ventricular cardiomyopathy, helping clinicians to interpret and translate genetic data into clinical practice.

Plakins, a versatile family of cytolinkers: roles in skin integrity and in human diseases

The plakin family consists of giant proteins involved in the cross-linking and organization of the cytoskeleton and adhesion complexes. They further modulate several fundamental biological processes, such as cell adhesion, migration, and polarization or signaling pathways. Inherited and acquired defects of plakins in humans and in animal models potentially lead to dramatic manifestations in the skin, striated muscles, and/or nervous system. These observations unequivocally demonstrate the key role of plakins in the maintenance of tissue integrity. Here we review the characteristics of the mammalian plakin members BPAG1 (bullous pemphigoid antigen 1), desmoplakin, plectin, envoplakin, epiplakin, MACF1 (microtubule-actin cross-linking factor 1), and periplakin, highlighting their role in skin homeostasis and diseases.

A possible cranio-oro-facial phenotype in Cockayne syndrome

Background

Cockayne Syndrome CS (Type A – CSA; or CS Type I OMIM #216400) (Type B – CSB; or CS Type II OMIM #133540) is a rare autosomal recessive neurological disease caused by defects in DNA repair characterized by progressive cachectic dwarfism, progressive intellectual disability with cerebral leukodystrophy, microcephaly, progressive pigmentary retinopathy, sensorineural deafness photosensitivity and possibly orofacial and dental anomalies.

Methods

We studied the cranio-oro-facial status of a group of 17 CS patients from 15 families participating in the National Hospital Program for Clinical Research (PHRC) 2005 « Clinical and molecular study of Cockayne syndrome ». All patients were examined by two investigators using the Diagnosing Dental Defects Database (D[4]/phenodent) record form.

Results

Various oro-facial and dental anomalies were found: retrognathia; micrognathia; high- arched narrow palate; tooth crowding; hypodontia (missing permanent lateral incisor, second premolars or molars), screwdriver shaped incisors, microdontia, radiculomegaly, and enamel hypoplasia. Eruption was usually normal. Dental caries was associated with enamel defects, a high sugar/carbohydrate soft food diet, poor oral hygiene and dry mouth. Cephalometric analysis revealed mid-face hypoplasia, a small retroposed mandible and hypo-development of the skull.

Conclusion

CS patients may have associated oro-dental features, some of which may be more frequent in CS children – some of them being described for the first time in this paper (agenesis of second permanent molars and radiculomegaly). The high susceptibility to rampant caries is related to a combination of factors as well as enamel developmental defects. Specific attention to these anomalies may contribute to diagnosis and help plan management.

Variant Carvajal syndrome with additional dental anomalies

BACKGROUND

This paper aims to review the case of a girl who presented with a number of dental anomalies, in addition to unusual skin, nail and hair conditions. Tragically an undiagnosed cardiomyopathy caused unexpected sudden death. The case is discussed with reference to a number of dermatological and oral conditions which were considered as possible diagnoses.

CASE REPORT

AW had been under long term dental care for prepubertal periodontitis, premature root resorption of primary teeth, soft tissue and dental anomalies, and angular cheilitis. Separately she had also been seen by several dermatologists with respect to palmar plantar keratosis, striae keratoderma, wiry hair and abnormal finger nails. Tragically the patient suffered a sudden unexpected death and the subsequent post mortem identified an undiagnosed dilated cardiomyopathy.

CONCLUSION

The most likely diagnosis is that this case is a variant of Carvajal Syndrome with additional dental anomalies. To date we have been unable to identify mutations in the desoplakin gene. We aim to emphasise the importance of recognising these dental and dermatological signs when they present together as a potential risk factor for cardiac abnormalities.

The DSPII splice variant is crucial for desmosome-mediated adhesion in HaCaT keratinocytes

Desmosomes are intercellular junctions specialised for strong adhesion that are prominent in the epidermis and heart muscle. Defective desmosomal function due to inherited mutations in the constitutive desmosomal gene desmoplakin (DSP) causes skin or heart disorders and in some instances both. Different mutations have different disease-causing molecular mechanisms as evidenced by the varying phenotypes resulting from mutations affecting different domains of the same protein, but the majority of these mechanisms remain to be determined. Here, we studied two mutations in DSP that lead to different dosages of the two major DSP splice variants, DSPI and DSPII, and compared their molecular mechanisms. One of the mutations results in total DSP haploinsufficiency and is associated with autosomal dominant striate palmoplantar keratoderma (PPK). The other leads to complete absence of DSPI and the minor isoform DSPIa but normal levels of DSPII, and is associated with autosomal recessive epidermolytic PPK, woolly hair and severe arrhythmogenic dilated cardiomyopathy. Using siRNA treatments to mimic these two mutations and additionally a DSPII-specific siRNA, we found striking differences between DSP isoforms with respect to keratinocyte adhesion upon cellular stress with DSPII being the key component in intermediate filament (IF) stability and desmosome-mediated adhesion. In addition, reduction in DSP expression reduced the amount of plakophilin 1, desmocollin (DSC) 2 and DSC3 with DSPI having a greater influence than DSPII on the expression levels of DSC3. These results suggest that the two major DSP splice variants are not completely redundant in function and that DSPII dosage is particularly important for desmosomal adhesion in the skin.