Phenotypic variability in LAMA3-associated amelogenesis imperfecta.

OBJECTIVE: Amelogenesis imperfecta (AI) is defined as inherited enamel malformations. LAMA3 (laminin alpha-3) encodes a critical protein component of the basement membrane (laminin-332). Individuals carrying heterozygous LAMA3 mutations have previously been shown to have localized enamel defects. This study aimed to define clinical phenotypes and to discern the genetic etiology for four AI kindreds. MATERIALS AND METHODS: Whole-exome analyses were conducted to search for sequence variants associated with the disorder, and micro-computed tomography (µCT) to characterize the enamel defects. RESULTS: The predominant enamel phenotype was generalized thin enamel with defective pits and grooves. Horizonal bands of hypoplastic enamel with chalky-white discoloration and enamel hypomineralization were also observed and demonstrated by µCT analyses of affected teeth. Four disease-causing LAMA3 mutations (NM_198129.4:c.3712dup; c.5891dup; c.7367del; c.9400G > C) were identified. Compound heterozygous MMP20 mutations (NM_004771.4:c.539A > G; c.692C > T) were also found in one proband with more severe enamel defects, suggesting a mutational synergism on disease phenotypes. Further analyses of the AI-causing mutations suggested that both α3A (short) and α3B (long) isoforms of LAMA3 are essential for enamel formation. CONCLUSIONS: Heterozygous LAMA3 mutations can cause generalized enamel defects (AI1A) with variable expressivity. Laminin-332 is critical not only for appositional growth but also enamel maturation.

First characterization of LTBP3 variants in two Moroccan families with hypoplastic amelogenesis imperfecta.

OBJECTIVES: To decipher and improve the molecular diagnosis of Hypoplastic Amelogenesis Imperfecta in Morocco. DESIGN: Using whole exome sequencing, we analyzed two Moroccan families with Hypoplastic Amelogenesis Imperfecta. The 2 patients from the first family had dental anomalies and short stature syndrome, brachyolmia and nephrocalcinosis with difference in severity, while the proband of the second family had Hypoplastic Amelogenesis Imperfecta with a suspicion of brachyolmia. RESULTS: We identified two novel LTBP3 homozygous variants, the c.2495delT deletion (p.Phe832SerfsTer36) and the c.3716 G>A (p.Cys1239Tyr) missense variant, respectively. Molecular modelling and stability analyses of the missense variant disclosed a possible destabilization of the wild-type structure. CONCLUSION: Although LTBP3 variants were related to this phenotype in various populations, we report the first LTBP3 variants in the Moroccan population, in families with Hypoplastic Amelogenesis Imperfecta.

Multiloop edgewise archwire treatment for a patient with a severe anterior open bite and amelogenesis imperfecta.

Amelogenesis imperfecta is a rare hereditary disorder that affects dental enamel and is often associated with an anterior open bite. Orthodontic treatment of a 16-year-old female patient with hypocalcified amelogenesis imperfecta and a 9-mm anterior open bite was presented. Radiographic examination revealed a steep mandibular plane angle, an increased lower face height, a Class II skeletal pattern, and a convex profile. Additionally, the patient had stainless steel crowns on all upper and lower posterior teeth and composite veneers on the upper anterior teeth. The patient was treated nonsurgically using a multiloop edgewise archwire (MEAW). MEAW mechanics allowed for successful correction of the anterior open bite, with significant reduction in the mandibular plane angle and improvement in the patient's profile. No fixed retainers were used, and the results remained stable 78 months after removal of orthodontic appliances. MEAW mechanics should be considered for patients with large anterior open bites, although this technique requires excellent patient compliance.

Two siblings with Heimler syndrome caused by PEX1 variants: follow-up of ophthalmologic findings.

BACKGROUND: Heimler syndrome (OMIM number #234580 and #616617) is a rare condition comprising sensorineural hearing loss (SNHL), nail abnormalities and amelogenesis imperfecta. In addition, patients with this syndrome can have retinal dystrophies. Heimler syndrome is caused by bi-allelic pathogenic variants in the PEX1 or PEX6 gene. Only few patients with this syndrome have been reported. We hereby describe two siblings with genetically confirmed Heimler syndrome and provide imaging of the ocular phenotype. MATERIALS AND METHODS: The medical records of the siblings were reviewed retrospectively. RESULTS: Both brother and sister were diagnosed with SNHL and amelogenesis imperfecta of the permanent teeth; one of the affected siblings also had nail abnormalities. Both patients presented to the ophthalmology department with suboptimal visual acuity, fundus abnormalities and intraretinal cystoid spaces. Full-field electroretinogram revealed a cone-rod dysfunction. A genetic analysis revealed a homozygous likely pathogenic variant c.3077 T > C (p.Leu1026Pro) in the PEX1 gene in both siblings. The parents are heterozygous carriers of the variant. CONCLUSION: We recommend performing regular ophthalmic examination in patients with Heimler syndrome since the ophthalmic manifestations can manifest later in life. Our patients presented with cone-rod dystrophy and intraretinal cystoid spaces. Review of the literature shows that the ocular phenotype can be very variable in patients with Heimler syndrome.

A Novel De Novo SP6 Mutation Causes Severe Hypoplastic Amelogenesis Imperfecta

Amelogenesis imperfecta (AI) is a heterogeneous group of rare genetic disorders affecting tooth enamel formation. Here we report an identification of a novel de novo missense mutation [c.817_818delinsAT, p.(Ala273Met)] in the SP6 gene, causing non-syndromic autosomal dominant AI. This is the second paper on amelogenesis imperfecta caused by SP6 mutation. Interestingly the identified mutation in this study is a 2-bp variant at the same nucleotide positions as the first report, but with AT instead of AA insertion. Clinical phenotype was much more severe compared to the previous report, and western blot showed an extremely decreased level of mutant protein compared to the wild-type, even though the mRNA level was similar.

Management guidelines for amelogenesis imperfecta: a case report and review of the literature.

BACKGROUND: Rehabilitation of the entire dentition with amelogenesis imperfecta (AI) tends to pose a great challenge to the clinician. Most of the cases of amelogenesis imperfecta are reported to be associated with skeletal and dental deformities which results in severe sensitivity of the dental tissues. CASE PRESENTATION: This clinical case report marks out the total restoration of the oral condition of a young Indian patient diagnosed with the hypoplastic type of amelogenesis imperfecta. Fixed metal ceramic prosthesis were planned to strengthen the masticatory activity, aesthetics, to banish the dental sensitivity and to build up the general persona of the patient. The patient was followed-up at 6 months, 1 year and 2 years intervals. Functional and esthetic impairment was not visible after the follow up period and the treatment outcome was successful. The entire treatment plan was intended to enhance the functional, esthetic and the masticatory component of the occlusal architecture. CONCLUSION: This case report details the presentation, characteristic radiographic findings, and management of a patient with an extremely rare condition of amelogenesis imperfecta.

Restorative treatment in a case of amelogenesis imperfecta and 9-year follow-up: a case report.

BACKGROUND: Amelogenesis imperfecta is a hereditary malformation showing various manifestations regarding enamel dysplasia. This case report shows a 9-year follow-up after restorative treatment of a 16-year old female patient affected by a hypoplastic type of amelogenesis imperfecta. The caries-free, hypersensitive teeth of the patient were restored by direct dentin adhesive composite restorations performed in total etch technique. CASE PRESENTATION: After rehabilitation the patient reported a marked improvement of the mastication ability and quality of life especially during food intake. Accumulation of plaque was reduced and the ability to perform adequate oral hygiene was improved. During follow-up of 9 years recurring secondary caries and debonding of fillings were recognized and retreated. CONCLUSIONS: The retrospective assessment exhibits that the performed restorative treatment prolonged the time until further treatment has to be considered, such as prosthetic treatment.

Amelogênese imperfeita do tipo hipoplásica: relato de dois casos familiares / Amelogénesis imperfecta del tipo hipoplásico: informe de dos casos familiares / Hypoplastic amelogenesis imperfecta: report of two family cases

RESUMO Introdução: Diariamente o cirurgião dentista se depara com diversos casos que exigem acurácia no diagnóstico inicial e atenção para o tratamento que irá ser proposto, uma dessas é a amelogênese imperfeita, que é uma rara alteração dentária de caráter hereditário. As características principais da amelogênese imperfeita são hipomineralização ou hipoplasia da matriz de esmalte, o que ocasiona descoloração, sensibilidade e fragilidade deste tecido, apresentando diferentes subtipos clínicos, sendo a variante hipoplásica a mais prevalente. Objetivo: Relatar dois casos de amelogênese imperfeita do tipo hipoplásica entre membros de uma mesma família, correlacionando-os. Apresentação do caso: O diagnóstico foi feito através dos exames clínico e radiográfico, além da correlação entre os achados clínicos encontrados em cada paciente e com outros familiares, sendo proposto um plano de tratamento multidisciplinar e consistente com a condição adequada. Conclusões: É importante para o cirurgião dentista estudar e conhecer essas alterações raras para poder estabelecer diagnóstico preciso. Além disso, deve-se ampliar a conduta clínica através de um planejamento individualizado e/ou familiar, tratando não apenas aspectos estéticos e funcionais, mas também psicológico e sociais(AU)

RESUMEN Introducción: Diariamente el cirujano dentista se enfrenta a varios casos que exigen precisión en el diagnóstico inicial y atención para el tratamiento que se propondrá, una de las cuales es la amelogénesis imperfecta, que es un rara alteración dental de carácter hereditario. Las características principales de la amelogénesis imperfecta son hipomeralización o hipoplasia de la matriz de esmalte, lo que ocasiona decoloración, sensibilidad y fragilidad de este tejido, con la presencia de diferentes subtipos clínicos, siendo la variante hipoplásica la más prevalente. Objetivo: Informar dos casos de amelogénesis imperfecta del tipo hipoplásica entre miembros de una misma familia, correlacionándolos. Presentación del caso: El diagnóstico se realizó a través de los exámenes clínicos y radiográficos, además de la correlación entre los hallazgos clínicos encontrados en cada paciente y con otros familiares, por lo que fue propuesto un plan de tratamiento multidisciplinario y consistente con la condición adecuada. Conclusiones: Es importante para el cirujano dentista que estudie y conozca estos cambios raros para poder establecer un diagnóstico preciso. Además, se debe ampliar la conducta clínica a través de una planificación individualizada y / o familiar, tratando no solo aspectos estéticos y funcionales, sino también psicológicos y sociales(AU)

ABSTRACT Introduction: Dental surgeons are confronted every day with several cases that require accuracy in the initial diagnosis and attention to the treatment that will be proposed. One of these is amelogenesis imperfecta, a rare hereditary tooth alteration. The main features of amelogenesis imperfecta are hypomineralization or hypoplasia of the enamel matrix resulting in discoloration, sensitivity and fragility of this tissue. Of the existing clinical subtypes, the hypoplastic variant is the most prevalent. Objective: Report and correlate two cases of hypoplastic amelogenesis imperfecta in members of the same family. Case presentation: The diagnosis was based on clinical and radiographic examination, as well as analysis of the correlation between the clinical findings obtained from each patient and other relatives. The treatment plan proposed was therefore multidisciplinary and appropriately consistent with the condition. Conclusions: It is important for dental surgeons to study and be aware of these rare changes to be able to establish an accurate diagnosis. On the other hand, clinical management should be broadened through individualized and/or family planning, paying attention not only to esthetic and functional aspects, but psychological and social as well(AU)

Orthognathic surgery with two-segment le fort i and sagittal split ramus osteotomies of open bite deformity in an amelogenesis imperfecta patient via virtual planning: A case report.

Amelogenesis imperfecta (AI) is an enamel defect and is often associated with the anterior open bite (AOB) and transverse maxillary deficiency. It is known that in such cases when AI and AOB appeared together, posterior maxillary impaction with or without bilateral mandibular ramus osteotomies is a frequently preferred treatment option. Virtual planning is more reliable rather than the conventional model surgery planning, especially for complicated cases. Usage area of virtual 3D anatomical models reconstructed from Cone Beam Computed Tomography (CBCT) data is expanding day by day for both diagnosis and surgical planning. The aim of this study is to present a patient with AI and AOB and transverse maxillary deficiency and management of this case with virtually planned two-segment Le fort I and sagittal split ramus osteotomies followed by prosthetic rehabilitation.

New missense variants in RELT causing hypomineralised amelogenesis imperfecta.

Amelogenesis imperfecta (AI) is a heterogeneous group of genetic diseases characterised by dental enamel malformation. Pathogenic variants in at least 33 genes cause syndromic or non-syndromic AI. Recently variants in RELT, encoding an orphan receptor in the tumour necrosis factor (TNF) superfamily, were found to cause recessive AI, as part of a syndrome encompassing small stature and severe childhood infections. Here we describe four additional families with autosomal recessive hypomineralised AI due to previously unreported homozygous mutations in RELT. Three families carried a homozygous missense variant in the fourth exon (c.164C>T, p.(T55I)) and a fourth family carried a homozygous missense variant in the 11th exon (c.1264C>T, p.(R422W)). We found no evidence of additional syndromic symptoms in affected individuals. Analyses of tooth microstructure with computerised tomography and scanning electron microscopy suggest a role for RELT in ameloblasts' coordination and interaction with the enamel matrix. Microsatellite genotyping in families segregating the T55I variant reveals a shared founder haplotype. These findings extend the RELT pathogenic variant spectrum, reveal a founder mutation in the UK Pakistani population and provide detailed analysis of human teeth affected by this hypomineralised phenotype, but do not support a possible syndromic presentation in all those with RELT-variant associated AI.

Expanding the genotypic spectrum of Jalili syndrome: Novel CNNM4 variants and uniparental isodisomy in a north American patient cohort.

Jalili syndrome is a rare multisystem disorder with the most prominent features consisting of cone-rod dystrophy and amelogenesis imperfecta. Few cases have been reported in the Americas. Here we describe a case series of patients with Jalili syndrome examined at the National Eye Institute's Ophthalmic Genetics clinic between 2016 and 2018. Three unrelated sporadic cases were systematically evaluated for ocular phenotype and determined to have cone-rod dystrophy with bull's eye maculopathy, photophobia, and nystagmus. All patients had amelogenesis imperfecta. Two of these patients had Guatemalan ancestry and the same novel homozygous CNNM4 variant (p.Arg236Trp c.706C > T) without evidence of consanguinity. This variant met likely pathogenic criteria by the American College of Medical Genetics guidelines. An additional patient had a homozygous deleterious variant in CNNM4 (c.279delC p.Phe93Leufs*31), which resulted from paternal uniparental isodisomy for chromosome 2p22-2q37. This individual had additional syndromic features including developmental delay and spastic diplegia, likely related to mutations at other loci. Our work highlights the genotypic variability of Jalili syndrome and expands the genotypic spectrum of this condition by describing the first series of patients seen in the United States.

A long-term clinical study on individuals with amelogenesis imperfecta.

BACKGROUND: The aims of this study are to present sociodemographic and familial characteristics, clinical and systemic findings, dental treatment needs, and concomitant dental anomalies in patients with amelogenesis imperfecta (AI) and to evaluate time-varying conditions in these long-term follow-up patients. MATERIALS AND METHODS: Records of patients with AI who were examined in the Department of Pediatric Dentistry between 1999 and 2017 were reviewed. Information about sociodemographic characteristics, history of AI and consanguinity in family, systemic conditions, reasons for referral to the clinic, oral hygiene habits and gingival health, occlusion findings, and performed treatments were gathered. Dental anomalies in radiographs were also evaluated. Baseline and final situations of the patients were assessed. Statistical analyses were performed. RESULTS: Of 75 patients aged 3-15 years with follow-ups up to 12 years, 34 had AI in their families and 15 were born from consanguineous marriages. Nephrocalcinosis has been observed in 5 patients. Main reasons for referral to the clinic were related to esthetic and hypersensitivity concerns. Twenty-two patients had gingivitis, and during follow-up process, gingival problems could not be completely prevented due to poor oral hygiene habits. Vertical dimension loss, open-bite, and cross-bite were seen in 16, 15, and 10 patients, respectively. Of the patients, 63% experienced restorative, 33% stainless steel crown, 17% endodontic, 8% prosthetic treatments, and 24% had retreatment needs. Concomitant dental anomalies were dens invaginatus, taurodontism, ectopic eruption, delayed eruption, hypodontia, and pulpal calcification. CONCLUSION: Early diagnosis and interventions considering the time-varying conditions with long-term follow-ups provide significant improvements in clinical maintenance of patients with AI.

Diversity of clinical, radiographic and genealogical findings in 41 families with amelogenesis imperfecta.

Amelogenesis imperfecta (AI) is a group of enamel development disorders that alter the structure and chemical composition of the tissue. There is great variability in the clinical presentation; according to Witkop, AI can be categorized into 14 subtypes, which makes its diagnosis extremely complex. OBJECTIVE: This study aimed to describe and determine the frequency of clinical and radiographic features and inheritance patterns found in 41 Chilean families diagnosed with diverse types of AI. MATERIAL AND METHODS: We analyzed the clinical records, photographs, pedigrees and radiographs of 121 individuals recruited between 2003 and 2016. All of the information was included in a database that was analyzed using the application Stata 14. RESULTS: The 72 affected individuals had average age of 16 years, and no sex association with the presence of AI was found. The most frequent clinical subtypes were as follows: 43% hypomature, 25% hypoplastic, 21% hypomature/hypoplastic, 7% hypocalcified and 4% hypocalcified/hypoplastic. The number of severely affected teeth was 22, which occurred in the patients with hypocalcified and hypocalcified/hypoplasic AI who presented the highest number of damaged teeth. Caries and periodontal disease were found in 47 and 32% of the patients, respectively. Malocclusions were observed in 43% of the individuals with AI, with open bite being the most frequent. Radiographically, the thickness of the enamel decreased in 51% of the patients, and 80% showed decreased radiopacity of the enamel compared to that of dentin. Autosomal dominant inheritance pattern was found in 37% of the families with hypoplastic AI, and autosomal recessive pattern was present in 56% of the other clinical subtypes, but more frequently in those affected with hypomature and hypocalcified AI. CONCLUSION: Of the five clinical subtypes, autosomal recessive hypomature, autosomal dominant hypoplastic and autosomal recessive hypomature/hypoplastic AI were the most prevalent subtypes in this group.

Diversity of clinical, radiographic and genealogical findings in 41 families with amelogenesis imperfecta

Abstract Amelogenesis imperfecta (AI) is a group of enamel development disorders that alter the structure and chemical composition of the tissue. There is great variability in the clinical presentation; according to Witkop, AI can be categorized into 14 subtypes, which makes its diagnosis extremely complex. Objective: This study aimed to describe and determine the frequency of clinical and radiographic features and inheritance patterns found in 41 Chilean families diagnosed with diverse types of AI. Material and Methods: We analyzed the clinical records, photographs, pedigrees and radiographs of 121 individuals recruited between 2003 and 2016. All of the information was included in a database that was analyzed using the application Stata 14. Results: The 72 affected individuals had average age of 16 years, and no sex association with the presence of AI was found. The most frequent clinical subtypes were as follows: 43% hypomature, 25% hypoplastic, 21% hypomature/hypoplastic, 7% hypocalcified and 4% hypocalcified/hypoplastic. The number of severely affected teeth was 22, which occurred in the patients with hypocalcified and hypocalcified/hypoplasic AI who presented the highest number of damaged teeth. Caries and periodontal disease were found in 47 and 32% of the patients, respectively. Malocclusions were observed in 43% of the individuals with AI, with open bite being the most frequent. Radiographically, the thickness of the enamel decreased in 51% of the patients, and 80% showed decreased radiopacity of the enamel compared to that of dentin. Autosomal dominant inheritance pattern was found in 37% of the families with hypoplastic AI, and autosomal recessive pattern was present in 56% of the other clinical subtypes, but more frequently in those affected with hypomature and hypocalcified AI. Conclusion: Of the five clinical subtypes, autosomal recessive hypomature, autosomal dominant hypoplastic and autosomal recessive hypomature/hypoplastic AI were the most prevalent subtypes in this group.

Oral Rehabilitation of Young Adult with Amelogenesis Imperfecta.

BACKGROUND: Amelogenesis imperfecta is a heterogeneous group of hereditary disorders that affect the enamel formation of the primary and permanent dentitions while the remaining tooth structure is normal. Appropriate patient care is necessary to prevent adverse effects on dental oral health, dental disfigurement, and psychological well-being. AIM: This clinical report presents a 27-year-old Chinese male with amelogenesis imperfecta (AI) and his restorative management. CASE REPORT: This clinical report presents a 27-year-old Chinese male with AI and his restorative management. Extraoral examination showed a skeletal class III profile and increased lower facial proportion. Intraorally, all the permanent dentition was hypoplastic with noticeable tooth surface loss and a yellow-brown appearance. This was complicated with a mild maloc-clusion and food packing on his posterior teeth. The patient wanted to improve his appearance and masticatory efficiency. Orthodontic treatment was performed to treat the mild malocclu-sion and create physiological interproximal spacing to minimize tooth preparation and facilitate oral hygiene. CONCLUSION: This report demonstrates how a multidisciplinary approach for the management of AI can achieve a predictable, functional, and esthetic outcome. Orthodontic treatment facilitated a conservative prosthodontic treatment outcome by selectively increasing interproximal space, minimizing tooth preparation, correcting posterior bilateral cross-bite, as well as an anterior reverse overjet and derotation of the canines. CLINICAL SIGNIFICANCE: This case report demonstrates the effective restoration of AI using a multidisciplinary approach to overcome crowding using a relatively conservative approach.

Prosthetic Rehabilitation of a Patient with Rare and Severe Enamel Renal Syndrome.

Dental rehabilitation of acute cases of enamel renal syndrome is challenging due to the absence of clinical reports. In the present case history report, examination of an 18-year-old patient revealed a complete lack of permanent teeth, as well as irregular and swollen bone and gingival morphology. Radiographs showed multiple impacted teeth in both arches. Creating a 1.5- to 2-cm interarch space was necessary for setting complete dentures. The ideal occlusal plane was chosen by combining two techniques (cephalometric radiograph and modification of the mandibular occlusal rim according to anatomical guidelines). Extraction of impacted teeth and recontouring of the alveolar process were performed simultaneously. The mandibular denture was connected through Locator abutments to two symphyseal implants. This pioneering clinical report will provide guidance to practitioners in the surgical intervention of patients with FAM20A (family with sequence similarities 20 A) gene mutations.

Mineral features of connective dental hard tissues in hypoplastic amelogenesis imperfecta.

OBJECTIVE: To explore the mineral features of dentin and cementum in hypoplastic Amelogenesis imperfecta AI teeth. MATERIALS AND METHODS: Forty-four (44) teeth cleaned and free of caries were used: 20 control and 24 affected by hypoplastic amelogenesis imperfecta. Thirty-two teeth were studied by pQCT, cut in sections, and analyzed under microradiography, polarized light microscopy, and confocal Raman spectroscopy. Eight teeth were observed under scanning electron microscope. Four teeth were used for an X-ray diffraction. The mineral density data were analyzed statistically with the Mann-Whitney U test, using GraphPad InStat software. RESULTS: Both coronal dentin and radicular dentin were less mineralized in AI teeth when compared to control (respectively 6.2% and 6.8%; p < .001). Root dentinal walls were thin and irregular, while the cellular cementum layers were thick, reaching sometimes the cervical region of the tooth. Regular dentinal tubules and sclerotic dentin areas were noticed. Partially tubular or cellular dysplastic dentin and hyper-, normo-, or hypomineralized areas were noticed in the inter-radicular areas of hypoplastic AI teeth. The main mineral component was carbonate hydroxyapatite as explored by Raman spectroscopy and X-ray diffraction. CONCLUSIONS: Dentin and cementum in hypoplastic AI teeth are (i) hypomineralized, (ii) constituted of carbonate hydroxyapatite, and (iii) of non-homogenous structure.

Estudio clínico, citogenético, molecular y de imagen de los pacientes con síndrome de Moebius del Hospital General 'Dr Manuel Gea González', Ciudad de México / Clinical, cytogenetic, molecular and image study of patients with Mobius syndrome at the General Hospital 'Dr Manuel Gea González', Mexico city

Introducción y Objetivo. El síndrome de Moebius es un trastorno congénito poco frecuente con prevalencia menor del 0.05%, caracterizado por parálisis facial congénita asociada a ausencia de abducción de los ojos por alteraciones del VI y VII nervios craneales, ya sea simétrica o asimétrica. La etiopatogenia cuenta con diferentes hipótesis: genética, vascular y teratógena. Existen pocos reportes en la literatura, y en especial en la latinoamericana, que describan las características clínicas y genéticas de estos pacientes. El presente estudio es el resultado del desarrollo de un equipo multidisciplinario en nuestro centro hospitalario para la descripción del espectro completo de la patología y así poder ofrecer los mejores tratamientos para cada uno de nuestros pacientes. Material y Método. Analizamos 115 pacientes con diagnóstico de síndrome de Moebius en sus 3 presentaciones: Moebius clásico, Moebius incompleto o Moebiuslike. Todos fueron sometidos a exploración física completa por un equipo multidisciplinario formado por ortopedistas, oftalmólogos, otorrinolaringólogos, ortodoncistas, neurólogos, pediatras, genetistas y cirujanos plásticos. Realizamos cariotipos a todos los pacientes para identificar anormalidades estructurales cromosómicas y enviamos muestras al Instituto Nacional de Medicina Genómica (INMeGen) para análisis molecular de cada paciente e identificación de posibles genes involucrados. Resultados. Un total de 52 pacientes (45%) fueron varones y 63 (55%) mujeres. Las manifestaciones clínicas fueron parálisis facial unilateral o bilateral con involucro de la abducción de los ojos en el 100%, asociada con estrabismo en el 62.6%, pie equino varo en el 46.1%, sindactilia simple 15.7%, paladar hendido 17.4%, micrognatia 17.4%, y síndrome de Poland 9.6%, entre otras manifestaciones. El análisis citogenético reportó 114 cariotipos de características estructurales normales y 1 solo caso de translocación recíproca balanceada entre el cromosoma 4 y 10. Dieciséis casos se asociaron a consumo materno de misoprostol en el primer trimestre del embarazo. El análisis molecular no se pudo concretar debido a falta de recursos materiales del INMeGen. Conclusiones. Hasta la fecha, y hasta donde hemos podido comprobar, esta es la cohorte de pacientes con síndrome de Moebius más grande reportada a nivel mundial en un solo centro hospitalario. La variabilidad de las presentaciones clínicas justifica el manejo por un equipo multidisciplinario tanto para el paciente como para los familiares. Este estudio abre las puertas para un campo de investigación mayor que nos pueda llevar a entender mejor la fisiopatología, intentar estableces causalidad y por lo tanto poder ofrecer mejores tratamientos, integrales y reproducibles (AU)

Background and Objective. Möbius syndrome is a rare congenital disease characterized by facial paralysis associated with an absence of abduction of the eyes for abnormalities in VI and VII cranial nerves. The pathogenesis has different hypothesis that include genetic, vascular and teratogenic causes. There are few reports in the literature and especially in Latin America to describe the clinical and genetic characteristics of these patients. The current study is the result of a multidisciplinary team developed in our center to describe the wide spectrum of the disease and offer the best treatment options to each of our patients. Methods. We analyzed 115 patients with the diagnosis of Möbius syndrome in its 3 presentations. All patients underwent a complete clinical examination by a multidisciplinary team formed by orthopedist, ophthalmologist, otolaryngologist, orthodontist, neurologist, plastic surgeon, pediatrician and geneticist. They underwent CTG banded karyotype to identify structural chromosome abnormalities. Results. Fifty two patients (45%) patients were male and 63 (55%) female. Clinical manifestations were found with unilateral or bilateral facial paralysis with VI nerve involvement in 100% of patients, associated with strabismus in 62.6%, 46.1% clubfoot, simple syndactyly 15.7%, 17.4% cleft palate, micrognathia 17.4%, Poland syndrome 9.6%, among others. Cytogenetic analysis showed normal karyotype in 114 patients and a reciprocal translocation between chromosome 4 and 10 in 1 patient. Sixteen cases of reported intake of misoprostol during the first trimester. Conclusions. As far as we know, this study is the largest global cohort reported in a single hospital of patients with Möbius syndrome. Variability of the clinical presentation justifies the management of these patients is a multidisciplinary team. This study opens the door for new studies that allow us to understand the pathophysiology of this disease and its response to different treatments (AU)

Enamel-renal syndrome in 2 patients with a mutation in FAM20 A and atypical hypertrichosis and hearing loss phenotypes.

Enamel-renal syndrome (OMIM #204690) is an uncommon disorder characterized by amelogenesis imperfecta and nephrocalcinosis and is caused by mutations in FAM20 A. We report 2 patients with enamel-renal syndrome who exhibited the typical features of this syndrome and a homozygous nonsense mutation in the FAM20 A gene (c.406 C>T), genetically confirming the diagnosis. They also exhibited 2 undescribed clinical features, hypertrichosis and hearing loss. Alterations in genes frequently associated with nonsyndromic hearing loss in the Brazilian population, including connexin 26 (GJB2), connexin 30 (GJB6) and mitochondrial 12 S rRNA (m.A1555 G mutation), were not found. These results suggest a putative function of FAM20 A in the development of the inner ear and in the formation of hair. The presence of nephrocalcinosis is a risk factor for renal impairment, and it is important to perform regular renal monitoring in order to avoid renal failure.