Clinical and genetic characterization of frontorhiny: report of 3 novel cases and discussion of the surgical management.

摘要

OBJECTIVES: To (1) define the nasal, columellar, and lip deformities of 3 patients with characteristics consistent with frontorhiny; (2) illustrate the embryologic correlation of the oronasal findings to the development of the median nasal prominence; (3) report the clinical manifestation in 3 patients from 2 unrelated families; (4) report a novel Y214X mutation in ALX3 ; and (5) describe the surgical reconstruction. METHODS: In this case series, we report 3 novel cases of frontorhiny from 2 different families. The surgical reconstruction technique is reviewed. Extension of the columellar medial crural cartilage into the upper lip cleft is examined histologically. Signed consent was granted for all patient photographs and specimens, and the study was approved by the institutional review committee of the University of California Davis The genetic sequencing of the ALX3 homeobox gene was performed in 2 of our 3 cases using standard commercially available sequencing kits. The genetic material in our third case was not available for analysis. RESULTS: Patients 1 and 2 were brothers from the same family. Both exhibited bifidity of their columella, a widened philtrum, poor nasal tip development, and low hairlines. Genetic sequencing in the 2 brothers confirmed the presence of a novel ALX3 homeobox mutation at the second exon (mutation Y214X). Patient 3 was a 4-year-old girl. She presented with an underdeveloped, widened nasal tip and a bifid columella. Her philtrum was widened and had a left-sided cartilaginous prominence. She also had a widened nasal root. Family history revealed no family members with the same features. CONCLUSIONS: Frontorhiny represents a new syndromic frontonasal malformation with consistent characteristic features. The genetic abnormality has now been found in 14 different patients. Careful scrutiny and classification of frontonasal deformities will expand our understanding of causes, genetic susceptibility, and treatment options.