Sleep-disordered breathing in children with achondroplasia assessed by polysomnography: a retrospective chart review

OBJECTIVES: Sleep-disordered breathing is a key childhood complication in children with achondroplasia. This retrospective study aimed to document the prevalence of sleep-disordered breathing in children with achondroplasia assessed by polysomnography.

DESIGN: The prevalence of sleep-disordered breathing assessed by polysomnography among children aged 0-18 years with achondroplasia from 2013 to 2024 at The Royal Children's Hospital, Australia, was retrospectively reviewed.

RESULTS: The cohort included 80 children with achondroplasia (54% females, 95% confirmed molecular diagnosis) with an average number of 3.6 polysomnographies collected per child (n=288). A total of 85% (68/80) had sleep-disordered breathing and 21% reported no prior symptoms. Sleep-disordered breathing subtypes included obstructive sleep apnoea in 81% (55/68), central sleep apnoea in 3% (2/68), mixed sleep apnoea in 7% (5/68) and primary snoring in 9% (6/68). Among those with obstructive and mixed sleep apnoea, 58% (35/60) had moderate or severe obstructive sleep apnoea. In 44 children, a corresponding MRI was evaluated for foramen magnum stenosis using the Achondroplasia Foramen Magnum Score. No correlation was found with sleep-disordered breathing severity (Spearman's coefficient (ρ)=0.03). Among 27 children who received a precision therapy for achondroplasia (vosoritide, n=18, infigratinib, n=8 and recifercept, n=1), the median respiratory disturbance index/hour improved from 2.7 (25th-75th percentile, (0.9-4.8)) to 1.1 (0.3-2.6) after 1 year of treatment compared with baseline.

CONCLUSIONS: Sleep-disordered breathing was present in 85% of 80 children with achondroplasia, with 21% being asymptomatic. Respiratory parameters did not correlate with foramen magnum stenosis severity and improved after 1 year of treatment in those treated with a precision therapy.