Otologic Axis and Sleep-Disordered Breathing in Achondroplasia: Age-Structured Cohort Findings

Background/Objectives: Achondroplasia is linked to distinctive ear-nose-throat (ENT) morbidity, yet quantitative age-structured profiles and actionable correlates remain incompletely defined. This study mapped ENT phenotypes in a consecutive cohort and examined the achondroplasia subset for prevalence, co-occurrence, age dynamics, and parsimonious risk models. Methods: Retrospective observational analysis (1 February 2023-31 January 2025). Narrative "ENT complications" were dictionary-mapped to five non-exclusive categories: otitis media, adenotonsillar/apnea-obstructive sleep apnea (OSA), audiologic/Eustachian-tube dysfunction (ETD), nasopharyngeal/upper-respiratory (URT), and extra-ENT. Proportions used Wilson 95% confidence intervals (CIs). Pairwise associations used Fisher's exact tests with Benjamini-Hochberg false discovery rate (BH-FDR). Age was summarized by a four-level age-class schema (AC-4: 0-2, 3-5, 6-12, ≥13 years) and a two-level sensitivity contrast (AC-2: ≤5 vs. >5 years). Results: Of 83 patients, 64 (77.1%) had achondroplasia. In achondroplasia, otitis media occurred in 51.6% and OSA in 28.1%; versus non-achondroplasia, ARDs were +35.8 and +28.1 percentage points (BH-FDR adjusted). Within achondroplasia, otitis media co-occurred with OSA (odds ratio [OR] 4.97; q = 0.012) and with ETD (OR 7.25; q = 0.012). OSA increased across AC-4 to school age (p-trend = 0.0548). In parsimonious models, otitis media independently predicted ETD and OSA. A five-item ENT-burden score discriminated otologic and adeno-tonsillar interventions (AUC 0.83-0.93). Conclusions: Achondroplasia shows a concentrated ENT burden dominated by otitis media and OSA, with large adjusted absolute differences versus non-achondroplasia. Otitis media functions as a practical clinical marker for both OSA and ETD, while a compact burden score may assist intervention triage.