The APERT Severity Scale: A Quantitative Tool for Risk Stratification in Apert Syndrome

Apert syndrome is a rare congenital disorder characterized by craniosynostosis, midface hypoplasia, and syndactyly. The multisystem complexity and lack of standardized surgical guidelines complicate diagnosis and treatment. This study introduces a quantitative severity scale for Apert syndrome to support objective risk stratification and personalized care.

The authors retrospectively reviewed children with Apert syndrome who were at least 11 years of age and treated from 1988 through 2024. A 5-domain severity scale based on literature review and clinical data was developed. Scoring was performed using preoperative photographs and documentation.

Of 65 identified patients, 37 (56.9%) met inclusion criteria. The mean follow-up age was 17.0 ± 5.0 years, with an average of 4.4 ± 2.2 craniofacial surgical procedures. Patients were scored from 1 (least severe) to 3 (most severe) in 5 domains: airway compromise, pressure (intracranial), eyes, retrusion of midface, and turribrachycephaly (APERT), with total scores ranging from 5 to 15. Severity categories were defined as mild (5 to 7), moderate (8 to 11), or severe (12 to 15). Fifteen patients (40.5%) had mild disease, 20 (54.1%) moderate, and 2 (5.4%) severe, with a mean score of 8.1 ± 1.8. Higher APERT scores correlated with increased surgical frequency ( r = 0.851; P < 0.001). Subscores in airway, pressure, eyes, and skull shape were also predictive. A score of 9 or greater predicted 6 or more surgical procedures with 100% sensitivity and 86.7% specificity.

The APERT score is the first quantitative classification of Apert syndrome severity, correlating with phenotypic burden and surgical volume. The APERT score may improve clinical communication, institutional comparisons, and risk-based treatment planning.