Spectrum of Disease in Hospitalized Newborns with Congenital Micrognathia: A Cohort of 3,236 Infants at North American Tertiary-Care Intensive Care Units.

OBJECTIVE: To describe the spectrum of disease and burden of care in infants with congenital micrognathia from a multicenter cohort hospitalized at tertiary care centers. STUDY DESIGN: The Children's Hospitals Neonatal Database was queried from 2010 through 2020 for infants diagnosed with micrognathia. Demographics, presence of genetic syndromes, and cleft status were summarized. Outcomes included death, length of hospitalization, neonatal surgery, and feeding and respiratory support at discharge. RESULTS: Analysis included 3,236 infants with congenital micrognathia. Cleft palate was identified in 1266 (39.1%). A genetic syndrome associated with micrognathia was diagnosed during the neonatal hospitalization in 256 (7.9%). Median (IQR) length of hospitalization was 35 (16, 63) days. Death during the hospitalization (n = 228, 6.8%) was associated with absence of cleft palate (4.4%, P < .001) and maternal Black race (11.6%, P < .001). During the neonatal hospitalization, 1289 (39.7%) underwent surgery to correct airway obstruction and 1059 (32.7%) underwent gastrostomy tube placement. At the time of discharge, 1035 (40.3%) were exclusively feeding orally. There was significant variability between centers related to length of stay and presence of a feeding tube at discharge (P < .001 for both). CONCLUSIONS: Infants hospitalized with congenital micrognathia have a significant burden of disease, commonly receive surgical intervention, and most often require tube feedings at hospital discharge. We identified disparities based on race and among centers. Development of evidence-based guidelines could improve neonatal care.

Expanding the phenotypic spectrum of ARCN1-related syndrome.

PURPOSE: This study aimed to describe the phenotypic and molecular characteristics of ARCN1-related syndrome. METHODS: Patients with ARCN1 variants were identified, and clinician researchers were connected using GeneMatcher and physician referrals. Clinical histories were collected from each patient. RESULTS: In total, we identified 14 cases of ARCN1-related syndrome, (9 pediatrics, and 5 fetal cases from 3 families). The clinical features these newly identified cases were compared to 6 previously reported cases for a total of 20 cases. Intrauterine growth restriction, micrognathia, and short stature were present in all patients. Other common features included prematurity (11/15, 73.3%), developmental delay (10/14, 71.4%), genitourinary malformations in males (6/8, 75%), and microcephaly (12/15, 80%). Novel features of ARCN1-related syndrome included transient liver dysfunction and specific glycosylation abnormalities during illness, giant cell hepatitis, hepatoblastoma, cataracts, and lethal skeletal manifestations. Developmental delay was seen in 73% of patients, but only 3 patients had intellectual disability, which is less common than previously reported. CONCLUSION: ARCN1-related syndrome presents with a wide clinical spectrum ranging from a severe embryonic lethal syndrome to a mild syndrome with intrauterine growth restriction, micrognathia, and short stature without intellectual disability. Patients with ARCN1-related syndrome should be monitored for liver dysfunction during illness, cataracts, and hepatoblastoma. Additional research to further define the phenotypic spectrum and possible genotype-phenotype correlations are required.

The role of double-step advancement genioplasty and bilateral coronoidectomy in Nager Syndrome: A case report.

AIM: To report the surgical management of bilateral mandibular coronoid processes hyperplasia and mandibular retrognathism associated with trismus and convex facial profile in an individual diagnosed with Nager syndrome (NS). CASE REPORT: A 21 years old female was referred to the Department of Oral and Maxillofacial Surgery, presenting limited mouth opening and an unpleasant convex facial profile. The tomography exhibited hyperplasia of mandibular coronoid processes with no evidence of intracapsular ankylosis of the temporomandibular joint. The treatment objectives were to increase mouth opening through a bilateral coronoidectomy and gain chin projection using the double-step advancement genioplasty technique. The 9-month postoperative follow-up revealed a 22.22% (6 mm) gain in jaw opening, improved masticatory function, and facial profile. CONCLUSIONS: The NS is a complex craniofacial anomaly due to its clinical heterogeneity. Thus, treatment planning must be done individually, considering the patients' main complaints and respecting the limitations regarding anatomy and availability of proper surgical materials. In the present case, a bilateral coronoidectomy associated with immediate physiotherapy improved the patient's mouth opening, and the double-step genioplasty promoted a much more significant chin advancement than would be obtained with the single-step traditional osteotomy.

Pierre Robin sequence: airway management via mandibular distraction: case report / Secuencia de Pierre Robin: manejo de vía aérea mediante distracción ósea mandibular: reporte de caso

Pierre Robin sequence is a set of congenital conditions characterized by the presence of micrognathia, glossoptosis, cleft palate and obstruction of the airways. The latter can lead to many other complications such as respiratory difficulties, apnea, weight loss and even death. Currently, mandibular distraction, or the lengthening of the mandibular bone, is the most common surgical procedure used to correct a retracted tongue and the airway obstruction it produces in patients with mandibular hypoplasia. The present paper reports the case of a 26-day-old male patient, who presented obstruction on the upper respiratory tract, mandibular retromicrognathia, and retracted tongue and cleft palate, all conditions characteristic to Pierre Robin sequence. The patient also had a medical record of orotracheal intubation due to respiratory difficulties. The subject underwent mandibular distraction surgery with a horizontal vector, which resulted in a satisfactorily cleared airway.

La secuencia de Pierre Robin es una afección congénita caracterizada por la presencia de micrognatia, glosoptosis, paladar hendido y obstrucción de la vía aérea, siendo ésta una de las principales características de la cual derivan varias complicaciones, entre ellas, dificultad respiratoria, apnea, pérdida de peso y hasta la muerte. En la actualidad la distracción ósea mandibular es la técnica quirúrgica de elección, que tiene como finalidad el alargamiento mandibular corrigiendo la posición posterior de la lengua, con la consecuente desobstrucción de la vía aérea en pacientes con hipoplasia mandibular. Se reporta caso clínico de paciente masculino con 26 días de nacido, que presentó obstrucción de la vía aérea superior, retromicrognatismo mandibular, retracción de la lengua y hendidura palatina, relacionado con la secuencia de Pierre Robin, con antecedentes de intubación orotraqueal por dificultad respiratoria, al cual se le realizó distracción ósea mandibular con vector horizontal, destacando resultados satisfactorios en la resolución de la obstrucción de la vía aérea.

"Ortoglossopelveplastia" e o algoritmo de sua utilização na sequência de Pierre-Robin / "Orthoglossopelveplasty" and the algorithm for its use in the Pierre Robin sequence

Introdução: Muitos pacientes portadores de sequência de Pierre Robin (micrognatia, glossoptose e obstrução de via aérea) apresentam o músculo genioglosso alterado, encurtado e retrátil, que impede a protração lingual, mantendo a parte anterior da língua verticalizada e seu volume deslocado em direção posterior. Isso pode corroborar para obstrução supraglótica, dificuldade alimentar e inversão das forças de estímulo do crescimento do corpo mandibular. Métodos: Estudo retrospectivo de pacientes com Pierre Robin tratados entre 2012 e 2017 pela equipe, com descrição da "ortoglossopelveplastia", que propõe uma modificação na glossopexia, soltando o genioglosso anômalo da sua inserção, liberando a língua para elevar seu terço anterior e avançar o volume de sua base, sendo auxiliada por ponto de tração da base lingual à sínfise mandibular. Apresentamos um algoritmo de tratamento proposto que prioriza a necessidade desta cirurgia, associada ou não à distração mandibular, de acordo com a gravidade da dificuldade respiratória e/ou alimentar. Resultados: São apresentados 12 casos de obstrução da orofaringe atendidos de 2012 a 2017, discutem-se suas prioridades, a ortoglossopelveplastia e se aplica o algoritmo proposto. Conclusão: A reorganização anatômica da musculatura em uma posição anteriorizada correta proporciona protração e funcionalidade à língua, com desobstrução da via aérea na orofaringe, melhora da função alimentar e do desenvolvimento mandibular, com baixa morbidade cirúrgica e poucas complicações.

Introduction: Several patients with the Pierre Robin sequence (micrognathia, glossoptosis, and airway obstruction) have an altered, shortened, and retractable genioglossus muscle that prevents protraction of the tongue and keeps the anterior part of the tongue vertical and its volume posteriorly displaced. This can contribute to supraglottic obstruction, feeding difficulty, and inversion of the growth stimulation forces of the mandibular body. Methods: A retrospective study of patients with the Pierre Robin sequence treated between 2012 and 2017 with "orthoglossopelveplasty," which includes modification of glossopexy, releasing the anomalous genioglossus of its insertion and releasing the tongue to raise its anterior third and advance the volume of its base using a traction suture of the tongue base to the mandible symphysis. We present a treatment algorithm that prioritizes the need for surgery associated, or not, with mandibular distraction in accordance with respiratory and/or feeding difficulty severity. Results: Twelve cases of oropharyngeal obstruction treated from 2012 to 2017 are presented, their priorities and orthoglossopleoplasty are discussed, and the proposed algorithm is applied. Conclusion: Anatomical reorganization of the musculature in a correct anterior position provides protraction and functionality to the tongue, clears the airway in the oropharynx, and improves the feeding function and mandibular development, with low surgical morbidity rates and few complications.

Jaws can be referred to as narrow or hypoplastic, but the term "atresia" is inaccurate!

ABSTRACT In order to lead to insights and discussion on proper use of Orthodontics and Pathology-related terminology, particularly in cases of smaller-than-usual maxilla and mandible - that is, anomalous ones -, this study compared the conceptual meaning of the term "atresia." It is considered improper when referring to maxilla and mandible with deficient growth compared to development that is satisfactory enough to reach normal size. To identify smaller maxilla and mandible, the most proper and accurate term is hypoplastic maxilla or mandible. This is because "atresia" stands for an anomaly related to lumen blockage in hollow organs, which is not the case for neither maxilla nor mandible. Hypoplastic maxilla or mandible can be properly and specifically referred to as micrognathia.

RESUMO Para induzir reflexões e discussões sobre o uso adequado da nomenclatura em Ortodontia e Patologia, para os casos em que a maxila e a mandíbula apresentam-se pequenas ou menores do que o habitual, ou seja, anômalas, comparou-se o significado conceitual do termo "atrésica". Esse termo não é adequado quando aplicado à maxila e à mandíbula para identificar situações em que houve um desenvolvimento com crescimento insuficiente para se chegar ao tamanho normal. Para identificar maxila e mandíbula menores, é mais adequado e preciso o uso do termo maxila ou mandíbula hipoplásica. Isso porque atresia representa uma anomalia por obstrução da luz ou lume em órgãos ocos, o que não ocorre na maxila ou na mandíbula. Maxila ou mandíbula hipoplásica também podem ser chamadas, apropriada e especificamente, de micrognatia.

Femoral-facial syndrome: A review of the literature and 14 additional patients including a monozygotic discordant twin pair.

Femoral-facial syndrome (FFS, OMIM 134780), also known as femoral hypoplasia-unusual face syndrome, is a rare sporadic syndrome associated with maternal diabetes, and comprising femoral hypoplasia/agenesis and a distinct facies characterized by micrognathia, cleft palate, and other minor dysmorphisms. The evaluation of 14 unpublished Brazilian patients, prompted us to make an extensive literature review comparing both sets of data. From 120 previously reported individuals with FFS, 66 were excluded due to: not meeting the inclusion criteria (n = 21); not providing sufficient data to ascertain the diagnosis (n = 29); were better assigned to another diagnosis (n = 3); and, being fetuses of the second trimester (n = 13) due to the obvious difficult to confirm a typical facies. Clinical-radiological and family information from 54 typical patients were collected and compared with the 14 new Brazilian patients. The comparison between the two sets of patients did not show any relevant differences. Femoral involvement was most frequently hypoplasia, observed in 91.2% of patients, and the typical facies was characterized by micrognathia (97%), cleft palate (61.8%), and minor dysmorphisms (frontal bossing 63.6%, short nose 91.7%, long philtrum 94.9%, and thin upper lip 92.3%). Clubfoot (55.9%) was commonly observed. Other observed findings may be part of FFS or may be simply concurrent anomalies since maternal diabetes is a common risk factor. While maternal diabetes was the only common feature observed during pregnancy (50.8%), no evidence for a monogenic basis was found. Moreover, a monozygotic discordant twin pair was described reinforcing the absence of a major genetic factor associated with FFS.

Association of polysomnographic parameters with clinical symptoms severity grading in Robin sequence patients: a cohort nested cross-sectional study.

OBJECTIVES: To evaluate the association of polysomnographic parameters with clinical symptom severity in Robin sequence (RS) patients. METHODS: All patients diagnosed as presenting with RS at Hospital de Clínicas de Porto Alegre from October 2012 to June 2016 were enrolled. They were classified as isolated RS, RS-plus, and syndromic RS. Polysomnography (PSG) was performed, except for those patients in need of respiratory support. Symptom severity was evaluated as defined by the Cole et al. CLASSIFICATION: Ordinal OR (for the chance of increase in one grade on the clinical severity scale) and R2 (determination coefficient from ordinal logistic regression) were computed from data analysis. RESULTS: A total of 80 participants were enrolled in the study. Fifty-five of these were able to undergo polysomnography. Worsening of the studied PSG parameters was associated with increase in clinical severity grading, as follows: desaturation index (OR 1.27; 95% CI; 1.07-1.51; R2 = 19.8%; p = 0.006); apnea/hypopnea Index (OR 1.13; 95% CI; 1.01-1.26; R2 = 12.5%; p = 0.02); sleep mean oxygen saturation (OR 0.16; 95% CI; 0.05-0.52; R2 = 22.6%; p = 0.002); oxygen saturation nadir (OR 0.73; 95% CI; 0.56-0.96; R2 = 10.0%; p = 0.02); percentage of time with oxygen saturation <90% (OR 9.49; 95% CI; 1.63-55.31, R2 = 37.6%; p = 0.012); and percentage of time presenting with obstruction (OR 2.5; 95% CI; 1.31-4.76; R2 = 25.1%; p = 0.006). CONCLUSIONS: Polysomnography parameters were associated with severity of clinical manifestations in patients with RS. Oxyhemoglobin saturation-based parameters had surprisingly significant R2 values. Therefore, those parameters, which have traditionally been undervalued in other clinical settings, should also be assessed in the polysomnographic evaluation of RS patients.

Tratamiento de anquilosis temporomandibular con materiales aloplásticos en niños: reporte de 3 casos / Treatment of temporomandibular joint ankylosis with alloplastic materials in children: report of 3 cases

La anquilosis de la articulación temporomandibular en niños continúa siendo una patología presente a pesar de los avances médicos y sociales. El tratamiento de esta patología en niños tiene como objetivos restablecer la apertura bucal y mejorar la estética facial, cuando se presentan hipoplasias o micrognatias asociadas. El objetivo del uso de materiales aloplásticos para el tratamiento de esta patología en niños es evitar la morbilidad y los gastos que ocasiona la toma y aplicación de injertos, para esto, durante 15 años, en la Unidad Médica de Alta Especialidad del Instituto Mexicano del Seguro Social, Torreón, Coahuila, México, Departamento de Cirugía Maxilofacial, se ha establecido el protocolo de tratar esta patología en niños con el uso de prótesis metálicas de cavidad glenoidea, en lugar de injertos costales o de otro tipo, además de tratar las hipoplasias o micrognatias en un mismo tiempo quirúrgico con el uso de aparatos distractores óseos, teniendo excelentes resultados a mediano plazo, sin daño a estructuras anatómicas ni a los procesos de crecimiento y desarrollo de los pacientes. Se utilizan prótesis prediseñadas de cromo, cobalto, molibdeno, que se adaptan adecuadamente a las estructuras óseas, siendo un material utilizado ya en otras áreas de la ortopedia en niños, concluyendo que se trata de una buena opción de tratamiento que disminuye el riesgo, frecuencia y costos de cirugías de mayor complejidad y que puede llevarse a cabo de manera segura y predecible. En este artículo se reportan tres casos de niños con anquilosis temporomandibular tratados con este método con buenos resultados (AU)

Temporomandibular joint ankylosis in children is actually a pathology still present despite the medical and social advances. The treatment of this pathology in children has restored the buccal opening and improve the facial aesthetics when hypoplasia and micrognathia are present. The purpose of using alloplastic material for treatment of this disease in children is to prevent morbidity and expenses related to making and implementing grafts, for this, for 15 years in the Medical Unit of High Specialty the Mexican Institute of Social Security, Torreon, Coahuila, Mexico, Department of Maxillofacial Surgery, has been established protocol to treatment this pathology in children with the use of metal glenoid prosthesis instead of rib grafts or otherwise in addition to treating hypoplasias or micrognatias in the same surgical time with the use of distracting devices bone, having excellent results in the medium term without damage to anatomical structures or processes of growth and development of patients. The prosthesis used predesigned chromium, cobalt, molybdenum, which are suitably adapted to the bone structures, with a material already used in other areas of orthopedics in children, concluding that this is a good treatment option that reduces the risk, and surgeries often cost more complex and can be performed safely and predictably. In this paper, three cases of children with temporomandibular ankylosis treated with this method with good results are reported (AU)

Secuencia malformativa de Pierre Robin: informe de un caso y revisión de la literatura / Pierre Robin sequence: case report and literature review

Durante la infancia es muy frecuente encontrar alteraciones del desarrollo,las cuales derivan de una defi ciente formación de las estructurasanatómicas durante la embriogénesis. Puede encontrarse un sinnúmerode alteraciones del desarrollo que afectan la región bucal y maxilofacial.La gran mayoría de estas alteraciones han sido catalogadas como síndromes de orden genético; sin embargo, no todas pueden describirse como tales, pues existen anomalías del desarrollo que aparecen como consecuencia de una deficiente embriogénesis de la región facial, provocando alteraciones anatómicas y funcionales, pero que se apartan de componentes genéticos y cromosómicos específi cos. La secuencia malformativa de Pierre Robin es una de ellas, ya que esta condición es producida por una afección inicial, de la cual derivarán otras afeccionesadicionales a nivel del paladar y de la mandíbula que ocasionarán en elpaciente dificultad para la alimentación y respiración. Debido a que las alteraciones de esta condición afectan directamente la cavidad bucal,es crucial que el odontólogo se encuentre familiarizado con esta anomalía. El objetivo del presente artículo es describir las característicasque configuran esta entidad nosológica mediante la exposición de un caso clínico y revisión de la literatura.

During childhood, it is frequent to find development disorders whichare linked to the weak formation of anatomic structures duringembryogenesis. It is possible to find a plethora of developmentdisorders that aff ect the oral and maxillofacial region. The majorityof these disorders has been classifi ed as genetic malformations butnot all can be described as such. That is because some developmentdisorders appear as a result of a defi cient embryogenesis of the face,producing thus anatomic and functional malformations but that standapart from genetic and chromosomic specifi c components. The Pierre Robin sequence is one of them, given that this condition is producedby an initial disorder, followed by other disorders in the palate andjaw; provoking alimentary and breathing disabilities in the patient.Due to these disorders and their impact on the mouth, it is crucial thatdentists be familiarized with such anomalies. The aim of this article isto describe the key characteristics that defi ne this disease through thepresentation of a clinical case and a literature review.

Targeted molecular investigation in patients within the clinical spectrum of Auriculocondylar syndrome.

Auriculocondylar syndrome, mainly characterized by micrognathia, small mandibular condyle, and question mark ears, is a rare disease segregating in an autosomal dominant pattern in the majority of the families reported in the literature. So far, pathogenic variants in PLCB4, GNAI3, and EDN1 have been associated with this syndrome. It is caused by a developmental abnormality of the first and second pharyngeal arches and it is associated with great inter- and intra-familial clinical variability, with some patients not presenting the typical phenotype of the syndrome. Moreover, only a few patients of each molecular subtype of Auriculocondylar syndrome have been reported and sequenced. Therefore, the spectrum of clinical and genetic variability is still not defined. In order to address these questions, we searched for alterations in PLCB4, GNAI3, and EDN1 in patients with typical Auriculocondylar syndrome (n = 3), Pierre Robin sequence-plus (n = 3), micrognathia with additional craniofacial malformations (n = 4), or non-specific auricular dysplasia (n = 1), which could represent subtypes of Auriculocondylar syndrome. We found novel pathogenic variants in PLCB4 only in two of three index patients with typical Auriculocondylar syndrome. We also performed a detailed comparative analysis of the patients presented in this study with those previously published, which showed that the pattern of auricular abnormality and full cheeks were associated with molecularly characterized individuals with Auriculocondylar syndrome. Finally, our data contribute to a better definition of a set of parameters for clinical classification that may be used as a guidance for geneticists ordering molecular testing for Auriculocondylar syndrome. © 2017 Wiley Periodicals, Inc.

Evolution of Obstructive Sleep Apnea in Infants with Cleft Palate and Micrognathia.

STUDY OBJECTIVES: Children with craniofacial anomalies are a heterogeneous group at high risk for obstructive sleep apnea (OSA). However, the prevalence and structural predictors of OSA in this population are unknown. We hypothesized that infants with micrognathia would have more significant OSA than those with isolated cleft palate ± cleft lip (ICP), and those with ICP would have more significant OSA than controls. We postulated that OSA severity would correlate with reduced mandibular size, neurodevelopmental scores, and growth. METHODS: Prospective cohort study. 15 infants with ICP, 19 with micrognathia, and 9 controls were recruited for polysomnograms, neurodevelopmental testing, cephalometrics (ICP and micrognathia groups) at baseline and a follow-up at 6 mo. RESULTS: Baseline apnea-hypopnea index (AHI) [median (range)] of the micrognathia group [20.1 events/h (0.8, 54.7)] was greater than ICP [3.2 (0.3, 30.7)] or controls [3.1 (0.5, 23.3)] (p = 0.001). Polysomnographic findings were similar between ICP and controls. Controls had a greater AHI than previously reported in the literature. Cephalometric measures of both midface hypoplasia and micrognathia correlated with OSA severity. Neurodevelopment was similar among groups. OSA improved with growth in participants with ICP and postoperatively in infants with micrognathia. CONCLUSIONS: Micrognathia, but not ICP, was associated with more significant OSA compared to controls. Both midface and mandibular hypoplasia contribute to OSA in these populations. OSA improved after surgical correction in most infants with micrognathia, and improved without intervention before palate repair in infants with ICP.

Nager syndrome and Pierre Robin sequence.

Nager syndrome is considered a rare genetic syndrome characterized by craniofacial and radial anomalies. Pierre Robin sequence is a triad that includes micrognathia, cleft palate and glossoptosis. The present patient had typical findings of Nager syndrome and Pierre Robin sequence. He progressed to severe respiratory distress, requiring mechanical ventilation and tracheostomy. At 1 year and 11 months, he had episodes of cardiorespiratory arrest and died. In the literature review, we identified the clinical description of 44 patients with Nager syndrome. Among them, 93.1% had micrognathia, 38.6% cleft palate and 11.3% glossoptosis. Only one (2.3%) had all three features, as observed in the present patient. Therefore, despite the fact that the features of Pierre Robin sequence are common, there are few patients who have the complete triad. It is noteworthy, however, that they may be associated with respiratory distress, which may put the patient's life at risk.

Prenatal diagnosis of femoral-facial syndrome: case report.

Femoral-facial syndrome (FFS), also known as femoral hypoplasia-unusual facies syndrome, is a rare condition characterized by a variable degree of unilateral or bilateral femoral hypoplasia associated with facial anomalies. This report describes a case of FFS diagnosed after 13 weeks of pregnancy following the detection of severe micrognathia and bilateral shortening of the femur in the fetus of a patient with DM. The sonographic evolution from the first trimester until birth is described. The clinical findings, the differential diagnosis with other pathologies characterized by hypoplasia femoral, and the prognosis are discussed.

Síndrome de Richner-Hanhart e suas manifestações otorrinolaringológicas: relato de caso / Richner-Hanhart Syndrome and its otorhinolaryngologic manifestations: case report

INTRODUÇÃO: A Síndrome de Richner-Hanhart se caracteriza pela ausência em grau variável de porções distais de uma ou mais extremidades, associada à micrognasia e microglossia severa. A etiologia desta rara síndrome permanece desconhecida. RELATO DE CASO: Neste artigo relatamos o caso de um paciente com Síndrome de Richner-Hanhart que apresentava ausência de terço anterior da língua, micrognatia, malformações dos pododáctilos e quirodáctilos, de pés e mãos, além de desvio de septo nasal para esquerda. COMENTÁRIOS FINAIS: O tratamento consiste em dieta com restrição de tirosina e acompanhamento contínuo com otorrinolaringologista e fisioterapeuta.

INTRODUCTION: Richner-Hanhart Syndrome is characterized by the absence in a variable degree of distal portions of one or more extremities, in association with micrognathia and severe microglossia. The etiology of this infrequent syndrome remains unknown. CASE REPORT: In this article, we report the case of a patient with Richner-Hanhart Syndrome, who showed an absence of the back third of the tongue, micrognathia, malformation of fingers and toes, as well as nasal septum deviation to the left. FINAL COMMENTS: The treatment comprises a tyrosine-restricted diet together with a continuous follow-up with an otorhinolaryngologist and a physiotherapist.

Polymorphisms of the noggin gene and mandibular micrognathia: a first approximation

Mandibular micrognathia is a deficiency in mandibular growth that prevents tooth contact during mastication, interferes with phonation and even causes sleep apnea. Studies show that mutant mice for chd (chordin) and nog (noggin) genes, which are modulators of the Bone Morphogenic Protein (BMP), had mandibular defects ranging from mandibular hypoplasia to micrognathia and agnathia. The human NOG gene was the first BMP antagonist identified and it is essential for various late events in mandibular development, which require modulation of the BMP activity. The aim of this work was to determine the presence of NOG gene polymorphisms in families with mandibular micrognathia and analyze its phenotype. Four families with mandibular micrognathia were included in this study. Blood samples were taken from the participating individuals through venipuncture and DNA was extracted. The fragments of interest were amplified using the Polymerase Chain Reaction (PCR) and the Single Nucleotide Polymorphisms (SNPs) of the NOG gene reported in the NCBI data base were analyzed through direct sequencing. The SNP rs1348322 was present in homozygote form in the subjects from all the families, where Cytosine is changed to Adenine in position 112 of the exon of the NOG gene. The SNP rs 1236187 did not show any clear result. This result suggests that there may be population polymorphism, or markers that are seldom polymorphic for our population. It is therefore necessary to continue with the search for the relationship of the NOG gene with mandibular micrognathia.

El micrognatismo mandibular, deficiencia en el crecimiento de la mandibula, no permite que los dientes entren en contacto durante la masticacion, interfiriendo con la fonacion y produciendo inclusive apnea del sueno. Estudios con ratones mutantes para el gen chordin (chd) o noggin (nog) moduladores de las proteinas morfogenicas oseas (BMP) presentaron defectos mandibulares, que van desde hipoplasia mandibular, pasando por micrognatia hasta agnatia. El gen NOG humano fue el primer antagonista de BMP identificado y es esencial para varios eventos tardios del desarrollo mandibular, que requieren modulacion de la actividad de las BMP. El objetivo del trabajo fue determinar la presencia de polimorfismos del gen NOG en pacientes con micrognatismo mandibular y analizar su fenotipo. Se tomaron 4 familias con micrognatismo mandibular, muestras de sangre fueron tomadas por venopuncion a los individuos participantes, el ADN fue extraido, se realizo la amplificacion de los fragmentos correspondientes a los polimorfismos rs 1236187 y rs 1348322 mediante PCR (Reaccion en Cadena de la Polimerasa) y se analizaron los SNPs del gen NOG reportados en la base de datos NCBI, mediante secuenciacion directa. El SNP rs 1348322, se presento en forma homocigota en los individuos de todas las familias, donde se da el cambio de una Citosina por una Adenina en la posicion 112 del exon del gen NOG. El SNP rs 1236187, no arrojo ningun resultado en forma clara. Este resultado sugiere que posiblemente pueden tratarse de polimorfismos poblacionales, o de marcadores poco polimorficos para nuestra poblacion, por lo tanto es necesario continuar en la busqueda de la relacion del gen NOG con el micrognatismo mandibular.

Síndrome de pirrre robín / Pierre Robin Syndrome

Se presenta el caso de una lactante menor de 5 meses de edad, internada en el Servicio de Medicina Hospital del Niñ@ Manuel Ascencio Villarroel con el diagnóstico de Síndrome de Pierre Robin y diversas malformaciones concomitantes: mucocele lingual, colpocefalia, hipoplasia de fosa posterior, nistagmus, paraparesia espástica, retraso del desarrollo, displasia bilateral de cadera, 6º ortejo en miembro inferior derecho, desnutrición crónica y reiterativos cuadros de neumonía intersticial.

A case of an infant under 5 months of age, admitted to the Medicine Service in the Hospital Manuel Ascencio Villarroel, diagnosed with Pierre Robin Syndrome and various malformations concomitant lingual mucocele, colpocephaly, hypoplastic posterior fossa, nystagmus, spastic paraparesis, developmental delay, bilateral hip dysplasia, 6th toe in the right leg, chronic malnutrition and repetitive tables interstitial pneumonía.