ALX-Related Frontonasal Dysplasias: Clinical Characteristics and Surgical Management.

AIM: The term frontonasal dysplasia (FND) represents a spectrum of anomalies and its genetics have not been well defined. Recently, the critical role of the aristaless-like homeobox (ALX) gene family on the craniofacial development has been discovered. In the present study, we aimed to propose a systematic surgical treatment plan for the ALX-related FNDs according to the genotypic classification as well as demonstrating their clinical characteristics to help surgeons diagnose the underlying pathology accurately.

DESIGN

Single-institution retrospective.

SETTING

Tertiary health care.

PATIENTS AND

METHODS

Eighty-nine FND cases were evaluated. Eight of them had ALX1-related FND3, 3 had ALX3-related FND1, and 2 had ALX4-related FND2. Phenotype characteristics of ALX-related FNDs were evaluated, and relevant surgical interventions were assessed.

RESULTS

The ALX1-related FND3 phenotype is striking due to the involvement of the eyes in addition to the presence of hypertelorism, facial clefts, and nasal deformities. A widened philtrum and prominent philtral columns are remarkable features of the ALX3-related FND1, whereas the ALX4-related FND2 has more severe deformities: severe hypertelorism, brachycephaly, large parietal bone defects, broad nasal dorsum, and alopecia. Facial bipartition, box osteotomies, eyelid coloboma repair, cleft lip and palate repair, nasal reconstruction, and fronto-orbital advancement can be performed in ALX-related FNDs based on the characteristics of each subtype.

CONCLUSIONS

This genetic classification system will help surgeon diagnose patients with FND with unique features and draw a roadmap for their treatment with a better surgical perspective.