A Family with Craniofrontonasal Syndrome and a Mutation (p.G151S) in the EFNB1 Gene: Expanding the Phenotype

Two novel mutations within FREM1 gene in patients with bifid nose

BACKGROUND

Bifid nose is a rare congenital deformity and the etiology is unknown. The purpose of this study was to report genetic variation in family of patients with bifid nose.

METHODS

Twenty-three consecutive patients who were diagnosed with mild bifid nose were operated with z-plasty from 2009 to 2021. Three underage patients (a pair of twins and a girl) from two family lines, who came to our hospital for surgical treatment, were enrolled. Whole exome sequencing and Sanger sequencing were conducted. Z-shaped flaps were created and the cartilago alaris major were re-stitched. Photographs and CT scan before and after surgery were obtained. Clinical outcomes, complications and patients' satisfaction were evaluated and analyzed. The follow-up time ranges from 2 to 3 years (2.4 ± 1.2 years).

RESULTS

Most patients were satisfied with the outcome (96.2%). The nasal deformities were corrected successfully with z-plasty technique in one-stage. FREM1 c.870_876del and c.2 T > C were detected with Whole exome sequencing, which have not been reported before. The results of Sanger sequencing were consistent with those of Whole exome sequencing.

CONCLUSIONS

The newly detected mutations of FREM1 have a certain heritability, and are helpful to make an accurate diagnosis and provide a better understanding of bifid nose mechanism. Z-plasty technique can be an effective technical approach for correcting mild bifid nose deformity.

Review of Etiology of Posterior Open Bite: Is There a Possible Genetic Cause?

Posterior open bite (POB) is one of the most severe malocclusions that can impair patients' masticatory functions, yet it is also a condition that is poorly understood and not well studied. Most reported cases are either sporadic or idiosyncratic with a diverse yet poorly understood etiology. Although primary failure of eruption (PFE), lateral tongue thrust, and certain medical syndromes or pathology of the temporomandibular joints have all been shown to cause POB, the complex interplay of environmental and genetic factors makes its etiopathogenesis a difficult subject to understand and investigate. Here, we provide a comprehensive review of the etiology of posterior open bite. Additionally, a genetic cause for POB is proposed through a report of an apparently non-syndromic familial case series with high POB penetrance across two generations. Further investigations of the gene(s) and mechanism(s) involved can not only provide a unique opportunity to better understand POB and the intricate muscular-occlusal relationship, but also offer powerful insight into the most effective approaches to clinical management of these (and potentially other) malocclusions.