Endocrine Abstracts

JOINT1214

Hypochondroplasia (HCH) is a rare genetic skeletal dysplasia causing disproportionate short stature. Few studies report its natural history. This retrospective study compared the medical impact of HCH among children with the general population in England. A real-world matched cohort study was conducted using electronic primary care medical records from January 1, 1998, through December 31, 2019, in the Clinical Practice Research Datalink linked to hospitalization and vital statistics data. Children (≤18 years of age [y]) with HCH were identified using a specific HCH diagnosis code (SNOMED:315057016) or a general code (ICD-10-CM:Q77. 4) without evidence of other growth conditions. Children with HCH were matched 1:4 to general population controls by sex, nearest birth year, and practice region. Event rates (events/100 person-years [PY]) and rate ratios (RRs; cases vs controls) were calculated for select comorbidities and healthcare use among children 0-10y and 11-18y. Overall, 225 children with HCH and 1067 matched controls were included. Mean follow-up time was approximately 9 years for children with HCH and 12 years for controls. Among both age groups, overall event rates of comorbidities (combined across all body systems) were higher among children with HCH vs controls (RR: 2. 59 [0-10y], 2. 88 [11–18y]). Ear, nose, and throat (ENT), respiratory, neurological, and developmental conditions were more frequent among children with HCH (1. 52-16. 85 episodes/100 PY), with autoimmune conditions also frequent among those aged 11-18 years (10. 06/100 PY); RRs ranged between 1. 84 and 13. 57, indicating significantly increased impact compared with controls (Table). Children with HCH had more healthcare visits than controls; general practice visits were most frequent (1149 visits/100 PY; RR, 1. 92 [0-10y] and 881 visits/100 PY; RR, 2. 14 [11-18y]). Though less common, inpatient admission rates were higher for children with HCH than controls (172 admissions/100 PY; RR, 8. 39 [0-10y] and 200 admissions/100 PY; RR, 10. 91 [11-18y]). Surgical procedures were infrequent but consistently higher among children with HCH vs controls, including orthopaedic procedures (1. 24 procedures/100 PY; RR, 11. 24 [0-10y] and 4. 12 procedures/100 PY; RR, 10. 17 [11-18y]). Children with HCH had substantially higher rates of comorbidities and healthcare resource utilization compared with the general paediatric population in England. Early, multidisciplinary management is needed for individuals with HCH to address health challenges.