Evaluation of the Mid and Lower Face in Three Females With Myhre Syndrome: Objective Methods to Supplement Subjective Assessment.

Myhre syndrome is a rare multisystem genetic disorder that is caused by de novo heterozygous gain-of-function variants in SMAD4. Patients with Myhre syndrome exhibit several phenotypes at different ages such as small size, autism, developmental delay, left-sided heart defects, and hearing loss and often have a characteristic facial appearance. The early clinical diagnosis of Myhre syndrome remains a major challenge, particularly in the first year of life. A Chinese male infant with syndactyly of fingers, hypertelorism, short palpebral fissures, and short philtrum was enrolled into the ENT department of the Chinese PLA General Hospital. Whole exome sequencing analysis was used to detect the disease-causing variant. A literature review of Myhre syndrome was also performed. A recurrent de novo missense variant c.1498A > G p.I500V(p. Ile500Val) in SMAD4 was detected confirming the clinical diagnosis of Myhre syndrome at the age of 38 days. The infant appears to be the youngest reported case of Myhre syndrome. At 23-month follow-up, the affected infant has dysmorphic facial features, growth retardation, and previously undescribed complete syndactyly. Review the literatures noted several common features in Myhre syndrome patients including hearing loss (72.7%), characteristic facial features (26.0%-54.5%), finger and toe abnormalities (3.9%-48.1%), short stature (45.5%), and respiratory (30.0%) and cardiovascular problems (65.0%). Clinicians should have a low threshold to perform genetic testing on patients with features suggesting Myhre syndrome even in the first year of life. Although some individuals with Myhre syndrome have normal hearing, early onset or progressive hearing loss usually occur in one or both ears in most patients, with remarkable phenotypic heterogeneity. Syndactyly may be minor such as typical 2-3 toe involvement, or more complicated as was observed in our patient.

Myhre syndrome (MIM 139210) is a rare autosomal‐dominant disorder characterised by short stature, brachydactyly, facial dysmorphism (short palpebral fissures, prognathism and short philtrum), developmental delay with mental retardation or/and behavioural troubles, progressive deafness of mixed conductive and sensory type and a trio of thickened skin, generalised muscle hypertrophy and restricted joint mobility. Life‐threatening complications (obesity, arterial hypertension and bronchopulmonary insufficiency) are observed in the course of the disease leading to an early death. In 2011, SMAD4 (SMAD family member 4) has been identified as the disease‐causing gene. All mutations identified so far are de novo heterozygous missense mutations, mainly involving Ile500. While SMAD4 inactivation is reported in juvenile polyposis syndrome with increased colorectal cancer risk, no increased tumoural risk has been observed in Myhre syndrome. SMAD4 is a key mediator of TGF‐β (transforming growth factor beta)/BMP (bone morphogenetic protein) signalling and the understanding of the consequences of SMAD4 mutations during development will decipher new regulatory network related to TGF‐β/BMP signalling. Key Concepts Myhre syndrome is a rare genetic condition of autosomal‐dominant inheritance due to SMAD4 mutations affecting Arg496 or Ile500 residues. Myhre syndrome is characterised by short stature, brachydactyly, facial dysmorphism, developmental delay, progressive deafness and a trio of thickened skin, generalised muscle hypertrophy and restricted joint mobility. Myhre syndrome is associated to a risk of early death due to possibly life‐threatening health conditions (obesity, arterial hypertension, bronchopulmonary insufficiency, laryngotracheal stenosis and pericarditis). Similar to mothers against decapentaplegic family member 4 ( SMAD4 ) encodes the common partner SMAD of the eight‐member family of SMAD proteins. SMAD4 aggregates into heterotrimer with the receptor‐regulated SMADs (R‐SMADs) once they are activated by phosphorylation by transmembrane serine–threonine receptor kinases in response to stimulation of TGF‐β, activin or BMP receptor pathways. The SMAD4 mutations identified in Myhre syndrome are expected to disturb the monoubiquitination of SMAD4 which occurs at Lys519 and also to disturb the function of the SMAD heterotrimer which regulates the expression of target genes. Germline heterozygous mutations in SMAD4 are known to cause juvenile polyposis syndrome (JPS) and JPS‐hereditary hemorrhagic telangiectasia. The SMAD4 mutations observed in JPS and JPS‐HHT include nonsense, missense, splice‐site changes and deletions, consistent with a loss‐of‐function mechanism. Increased tumoural risk has not been observed so far in Myhre syndrome. The development of tissue‐specific mouse models of Smad4 deficiency further highlighted the important role of Smad4 in a wide range of embryonic developmental processes.

peer reviewed

Myhre syndrome (OMIM 139210) is a rare developmental disorder inherited as an autosomal dominant trait and caused by a narrow spectrum of missense mutations in the SMAD4 gene. The condition features characteristic face, short stature, skeletal anomalies, muscle pseudohypertrophy, restricted joint mobility, stiff and thick skin, and variable intellectual disability. While most of the clinical features manifest during childhood, the diagnosis may be challenging during the first years of life. We report on the evolution of the clinical features of Myhre syndrome during childhood in a subject with molecularly confirmed diagnosis. The clinical records of 48 affected patients were retrospectively analysed to identify any early clinical signs characterizing this disorder and to better delineate its natural history. We also note that pericarditis and laryngotracheal involvement represent important life-threatening complications of Myhre syndrome that justify the recommendation for cardiological and ENT follow-up for these patients. Short length/stature, short palpebral fissures, and brachydactyly with hyperconvex nails represent signs/features that might lead to the correct diagnosis in the first years of life and direct to the proper molecular analysis. We underline the clinical relevance of pericarditis and laryngotracheal stenosis as life-threatening complications of this disorder and the need for careful monitoring, in relation to their severity. • The clinical and radiological signs of the disease in children older than 7-8years. • Pericarditis, sometimes occurring with constrictive pericardium requiring pericardiectomy, has been reported as a recurrent feature but has not been adequately stressed in previous literature. What is New: • Short length/stature, short palpebral fissures, brachydactyly with hyperconvex nails represent clinical signs that might lead to diagnosis in the first years of life. • Review of the literature showed that pericarditis and laryngotracheal complications represent major recurrent issues in patients with Myhre syndrome.

Infinite cornucopia: The future of education and training in oral and maxillofacial surgery

Myhre syndrome is a rare disorder characterized by pre- and postnatal short stature, brachydactyly, facial dysmorphism (short palpebral fissures, maxillary hypoplasia, prognathism and short philtrum), thick skin, muscular-appearing body build, decreased joint mobility, mixed hearing loss, and cleft lip and palate. Other clinical features include skeletal dysplasia, developmental delay with intellectual disability and/or behavioral disturbance, cardiac defects, cryptorchidism, and bone anomalies. The disease is caused by recently identified SMAD4 mutations. Here we describe a 7-year-old boy with a molecularly proven Myhre syndrome who presented life-threatening recurrent pericarditis and systemic inflammatory symptoms that required treatment with steroid and recombinant interleukin-1 receptor antagonist.

Myhre syndrome is a rare disorder characterized by pre- and postnatal short stature, brachydactyly, facial dysmorphism (short palpebral fissures, maxillary hypoplasia, prognathism and short philtrum), thick skin, muscular-appearing body build, decreased joint mobility, mixed hearing loss, and cleft lip and palate. Other clinical features include skeletal dysplasia, developmental delay with intellectual disability and/or behavioral disturbance, cardiac defects, cryptorchidism, and bone anomalies. The disease is caused by recently identified SMAD4 mutations. Here we describe a 7-year-old boy with a molecularly proven Myhre syndrome who presented life-threatening recurrent pericarditis and systemic inflammatory symptoms that required treatment with steroid and recombinant interleukin-1 receptor antagonist.

Background: Myhre syndrome is a rare connective tissue disorder caused by heterozygous pathogenic variants in the SMAD4 gene. Although recognizing Myhre syndrome in early childhood is challenging, it is important to manage airway stenosis in patients with Myhre syndrome. Case Presentation: We report the case of a 2-month-old boy who initially presented with severe multilevel airway stenosis, dysmorphic face, and multiple abnormalities. Lung fibrosis and mild aortic valve stenosis were additionally observed on follow-up examinations. A heterozygous missense variant, c.1499T>C (p.Ile500Thr), in SMAD4 was identified through exome sequencing. Tracheostomy was performed, and the patient has maintained stable respiration through a customized tracheostomy tube with a home ventilator. Conclusions: Patients who have dysmorphic face, airway stenosis, and cardiovascular anomalies that do not fit the diagnosis of common syndromes should be evaluated for rare diseases, including Myhre syndrome. Since respiratory complications can be life threatening, early diagnosis and suitable intervention are necessary.

Dual-degree oral and maxillofacial surgery: evidence-based view of Chilean candidates

David Stanley Precious (1944-2015)

To What Extent is Each Area of Oral-Maxillofacial Surgery Practiced in the United States Today?

Objective To understand the current status of the discipline and work out the developmental tactics of oral and maxillofacial surgery in China. Methods A questionnaire on the status of oral and maxillofacial surgery was designed and dispatched to the departments of stomatology in general hospitals at the level of prefecture or higher, stomatological hospitals and schools of stomatology. The contents of the questionnaire included the scale, manpower, professional extent, amount of clinical work and professional training of oral and maxillofacial surgery. The current status was compared with the previous status 5 and 10 years ago. Results In the most institutions which were surveyed, the number of oral and maxillofacial surgeons, beds and out-patients increased, the professional extent enlarged, and the clinical level improved. However, the above-mentioned clinical parameters decreased in some basic level institutions. The number of graduate students and trainees of oral and maxillofacial surgery decreased in one-third of institutions. Conclusions The discipline of oral and maxillofacial surgery is continuously developing, but it is weakened in some basic level institutions. An effective developmental tactics should be carried on to improve the competition capability of the discipline. Key words: Questionnaires; Surgery, oral; Oral and maxillofacial surgery

Musings of Chairs

Recruitment of Future Maxillofacial Surgeons

Objective To assess the feasibility,acceptability and effects of mini-clinical evaluation exercise(mini-CEX)for performance evaluation among students or graduate students of oral and maxillofacial surgery outpatient or emergency department.Methods From 2010 to 2011,the clinical performances of forty medical college students in the outpatient department of oral and maxillofacial surgery or department of oral emergency were evaluated by three doctors.Four to eight times assessments were performed for every student during the entire study period.The patients were elected randomly in the outpatient or emergency department of oral and maxillofacial surgery,who were informed and consent to the study.Every participant assessed the evaluation at the end of the evaluation.We analyzed the processes and results of the evaluation,and assessed the effects of mini-CEX in the performance evaluation among students or graduate students of oral and maxillofacial surgery outpatient or emergency department.Results We completed 265 successfully evaluations.It took 25.3 minutes for the evaluation,and 4.1 minutes for the feedback in mean.At the end of teaching course,all students met the teaching requirement.All participants were satisfied with this kind of mini-CEX,and all participants believed that mini-CEX was a good evaluation and learning tool,too.Conclusions The mini-CEX is a reliable tool for learning and performance evaluation of students or graduate students of oral and maxillofacial surgery outpatient or emergency department,and is acceptable and well received by both students and supervisors. Key words: Mini-clinical evaluation exercise; Oral and maxillofacial surgery; Clinical teaching; Application