Endocrine Abstracts

JOINT1215

Hypochondroplasia (HCH) is a rare genetic skeletal dysplasia causing disproportionate short stature secondary to pathogenic variants in the gene fibroblast growth factor receptor 3 (FGFR3). This retrospective study compared the medical impact of HCH among adults with the general population in England from 1998 to 2019. A real-world matched cohort study was conducted using electronic primary care medical records from the Clinical Practice Research Datalink. Adults with HCH identified using a specific HCH diagnosis code (SNOMED:315057016) or a general code (ICD-10-CM:Q77. 4) were split into 4 age groups (19-29, 30-49, 50-69, and ≥70 years of age [y]) and matched 1:4 with controls by sex, nearest birth year, and region. Event rates (events/100 person-years [PY]) and rate ratios (RR; cases vs controls) were calculated for selected comorbidities and healthcare use. Overall, 385 adults with HCH and 1373 matched controls were included: 136 and 572 (19-29y), 181 and 592 (30-49y), 49 and 142 (50-69y), and 19 and 67 (≥70y), respectively. Across ages, mean follow-up time ranged from 6 to 8 years for adults with HCH and 11 to 14 years for controls, respectively. Comorbidity event rates were higher among adults with HCH vs controls and generally increased with age; the highest rates were for respiratory, mental health, cardiovascular, and orthopaedic events (Table). Although surgical procedures were infrequent, orthopaedic surgery rates were higher among adults with HCH than controls. Adults with HCH utilized more healthcare resources than controls, and rates generally increased with age. General practice visits were most frequent (range, 1055. 02–2778. 55 visits/100 PY), followed by inpatient admissions (range, 319. 68–520. 46 visits/100 PY). In all age groups, mortality rates were higher for individuals with HCH than controls, peaking among those aged 30 to 49 years (RR: 3. 31 [19-29y], 18. 41 [30-49y], 4. 92 [50-69y], 1. 72 [≥70y]). Rates of certain conditions typically increase with age; the increase is more pronounced for people with HCH. Results highlight the medical burden of HCH and the importance of lifelong multidisciplinary management.