Prevalence and characteristics of paediatric X-linked hypophosphataemia in Australia and New Zealand: Results from the Australian and the New Zealand Paediatric Surveillance Units survey.

BACKGROUND: X-linked hypophosphataemia (XLH) is the most common heritable form of rickets. Prevalence data varies across the literature between 1 in 20,000 and 1 in 200,000 per population. METHODS: Australian and New Zealand Paediatric Surveillance Units collected cross-sectional data from paediatricians on existing cases to estimate prevalence and characteristics of paediatric XLH in Australia and New Zealand. RESULTS: Seventy-five cases in Australia and 18 cases in New Zealand were identified. Estimated minimum prevalence based on these cases was 1.33 (1.04-1.66) per 100,000 and 1.60 per 100,000 (95%CI 0.97-2.58) in Australia and New Zealand respectively, with actual prevalence likely higher due to incomplete ascertainment. Despite a family history in most cases, delayed diagnosis was common, with 49 % diagnosed after 2 years of age. Delayed diagnosis was more common in sporadic versus familial cases. Most common clinical characteristics included leg bowing (89 %), bone and joint pain (68 %), abnormal gait (57 %) and short stature (49 %). There was a significant burden of orthopaedic disease and surgeries and a high rate of complications of nephrocalcinosis and hyperparathyroidism (32 % and 20 % respectively). Additionally, while guidelines stress the importance of multidisciplinary care, many did not have access to recommended health professionals, with only 3 % seeing a psychologist and 68 % seeing a dentist. This is despite the high psychological burden of XLH and a significant proportion (41 %) of this cohort having dental issues (tooth abscess, dental capping, tooth extraction). There were two cases from NZ without data available. Of the 91 cases with data collected, 46 % were on burosumab therapy. Consistent with clinical trials, those on burosumab had a higher serum phosphate levels (p < 0.001) at most recent follow-up. Three cases reported cancellation of orthopaedic surgery due to improvement in lower limb deformity after commencement of burosumab. CONCLUSION: These data describe the multisystem burden of disease for children with XLH with care impacted by delayed diagnosis and a lack of access to many health professionals, especially psychological support.

Burden of eating disorders in 5-13-year-old children in Australia.

OBJECTIVE: To collect nationally representative epidemiological data on early-onset eating disorders (EOEDs) in children. DESIGN: Prospective, active surveillance using the Australian Paediatric Surveillance Unit with key informant design. SETTING: Child health specialists in Australia (July 2002 to June 2005). PATIENTS: Incident cases of EOEDs in children aged 5-13 years. MAIN OUTCOME MEASURES: Disease rates, demographic characteristics, clinical features and complications, hospitalisation, psychological comorbidity, and concordance of clinical features with Diagnostic and statistical manual of mental disorders, fourth edition (DSM-IV) criteria. RESULTS: We identified 101 children aged 5-13 years with EOEDs (median age, 12.2 years; range, 5.5-13.9 years), of whom one in four were boys. Most were hospitalised (78%), and the mean duration of hospitalisation was 24.7 days (range, 1-75 days). More than 70% of inpatients were admitted to specialised eating disorder units in paediatric teaching hospitals. Among inpatients, 37% met DSM-IV diagnostic criteria for anorexia nervosa; although 61% had life-threatening complications of malnutrition, only 51% met weight criteria. Psychological symptoms were similar to those in adults with anorexia nervosa: 67% of inpatients met both psychological diagnostic criteria for anorexia nervosa (fear of weight gain/fatness and misperception of body shape). Of 19 postmenarchal girls, 18 had secondary amenorrhoea. Nasogastric feeding was used in 58% of inpatients, and 34% received psychotropic medications. CONCLUSIONS: This is the first prospective national study of EOEDs. It demonstrates the limitations of applying DSM-IV diagnostic criteria for anorexia nervosa to young children; the high proportion of boys affected by EOEDs; and the significant psychological comorbidity and high frequency of hospitalisation associated with EOEDs. Potentially life-threatening medical complications are common at presentation, suggesting possible missed diagnoses and a need for education of health professionals. The study underlines the severity of EOEDs and the need for joint medical and psychiatric specialist management.