Síndrome de Saethre-Chotzen: a propósito de un caso / Saethre-Chotzen syndrome: a case report

El síndrome de Saethre-Chotzen es un síndrome malformativo craneofacial caracterizado por una sinostosis de las suturas coronales y alteraciones de extremidades. Tiene una prevalencia de 1 de cada 25 000-50 000 recién nacidos vivos. Se presenta el caso de un neonato sin antecedentes de interés con alteraciones craneofaciales al nacer. Ante los rasgos fenotípicos del paciente, se realizó una tomografía axial computada craneal, que mostró la fusión parcial de la sutura coronal y evidenció la presencia de huesos wormianos en localización metópica y lambdoidea derecha. Con la sospecha clínica de síndrome malformativo craneofacial, se solicitó análisis del exoma dirigido, que confirmó que el paciente era portador heterocigoto de la variante patogénica c.415C>A, que inducía un cambio de prolina a treonina en la posición 139 del gen TWIST1, responsable del síndrome. La presencia de huesos wormianos, hallazgo no descrito hasta ahora en la literatura, amplía la variabilidad fenotípica conocida de este síndrome.

The Saethre-Chotzen syndrome is a craniofacial malformation syndrome characterized by synostosis of coronal sutures and limb anomalies. The estimated prevalence of this syndrome is 1 in 25 000-50 000 live births. We present a case report of a neonate, without relevant family history, who presented craniofacial alterations at birth. Given the phenotypic features, a cranial computed tomography scan was performed, showing partial fusion of the coronal suture, evidencing the presence of wormian bones in the metopic and right lambdoid location. With the clinical suspicion of craniofacial malformation syndrome, an analysis of the directed exome was requested confirming that the patient is a heterozygous carrier of the pathogenic variant c.415C>A, which induces a change of proline to threonine at position 139 of the TWIST1 gene, responsible for Saethre-Chotzen syndrome.The presence of wormian bones, a finding not described so far in the literature, extends the well-known phenotypic variability of this syndrome.

Genetic Syndromes Associated with Craniosynostosis

Craniosynostosis is defined as the premature fusion of one or more of the cranial sutures. It leads not only to secondary distortion of skull shape but to various complications including neurologic, ophthalmic and respiratory dysfunction. Craniosynostosis is very heterogeneous in terms of its causes, presentation, and management. Both environmental factors and genetic factors are associated with development of craniosynostosis. Nonsyndromic craniosynostosis accounts for more than 70% of all cases. Syndromic craniosynostosis with a certain genetic cause is more likely to involve multiple sutures or bilateral coronal sutures. FGFR2, FGFR3, FGFR1, TWIST1 and EFNB1 genes are major causative genes of genetic syndromes associated with craniosynostosis. Although most of syndromic craniosynostosis show autosomal dominant inheritance, approximately half of patients are de novo cases. Apert syndrome, Pfeiffer syndrome, Crouzon syndrome, and Antley-Bixler syndrome are related to mutations in FGFR family (especially in FGFR2), and mutations in FGFRs can be overlapped between different syndromes. Saethre-Chotzen syndrome, Muenke syndrome, and craniofrontonasal syndrome are representative disorders showing isolated coronal suture involvement. Compared to the other types of craniosynostosis, single gene mutations can be more frequently detected, in one-third of coronal synostosis patients. Molecular diagnosis can be helpful to provide adequate genetic counseling and guidance for patients with syndromic craniosynostosis.

Correção de estrabismo em paciente com síndrome de Saethre-Chotzen / Strabismus surgery in a patient with Saethre-Chotzen syndrome

A síndrome de Saethre-Chotzen é uma doença rara, que pode causar alterações craniofaciais e estrabismo. A incidência é de 1 para 50.000 nascidos vivos. A inteligência costuma ser normal, mas alguns casos podem ter retardo mental. Crianças com essa síndrome devem ser acompanhadas por uma equipe multidisciplinar. A correção do estrabismo nesses pacientes pode ser mais difícil, devido à ocorrência frequente de inserções anômalas dos músculos extraoculares. Recomendam-se técnicas de imagem para avaliar eventuais alterações das inserções e trajeto dos músculos extraoculares...

Saethre-Chotzen syndrome is a very rare congenital syndrome characterized by craniosynostosis. The incidence of it is around 1: 50,000 live births. Intelligence is usually normal, but a few affected individuals may have mild to moderate mental retardation. Children with Saethre-Chotzen syndrome should be evaluated by members of an experienced interdisciplinary team as treatment usually involves many different specialities. The strabismus surgery in these patients is difficult, because they usually have anomalous insertion and misdirection of the extraocular muscles. Imaging techniques are recommended in order to investigate the anatomical aspects of the extraocular muscles and their insertions...

Síndrome de Saethre-Chotzen: suas alterações dismórficas. Relato de caso / Saethre-Chotzen syndrome: facial dysmorphic features. A case report

Introdução: A síndrome de Saethre-Chotzen é um distúrbio raro de herança autossômica dominante causada por mutações no gene TWIST, localizado no lócus 7p21; os pacientes apresentam defeitos na cabeça (plagiocefalia e assimetría facial) e na parte distal das extremidades, dedos encurtados e ligados pela persistência de uma membrana entre eles (sindactilia). Objetivo: Apresentar um relato de caso da síndrome de Saethre-Chotzen, discutindo as características diagnósticas que diferenciam essa síndrome dos outros tipos de craniossinostoses e o diagnóstico diferencial. Descrição: Estudante de 11 anos apresentando os seguintes sinais clínicos: plagiocefalia decorrente de craniossinostose, acrobraquicefalia, assimetria facial e hemimelia, com ausência da porção distal do antebraço direito. Comentários: Apresentamos um caso ilustrativo da síndrome de Saethre-Chotzen, que constitui a mais frequente das doenças com craniossinostoses e descrevemos as importantes alterações faciais dismórficas da síndrome.