DOI: 10.1210/clinem/dgae069 ISSN: 0021-972X

The diagnostic odyssey in children and adolescents with X-linked hypophosphataemia: population-based, case-control study

Freya Boardman-Pretty, Ashley Kieran Clift, Hadley Mahon, Nadine Sawoky, M Zulf Mughal
  • Biochemistry (medical)
  • Clinical Biochemistry
  • Endocrinology
  • Biochemistry
  • Endocrinology, Diabetes and Metabolism



X-linked hypophosphataemia (XLH) is a rare genetic disorder causing renal phosphate wasting, which predicates musculoskeletal manifestations such as rickets. Diagnosis is often delayed.


To explore the recording of clinical features, and the diagnostic odyssey of children and adolescents with XLH in primary care electronic healthcare records (EHR) in the United Kingdom.


Using the Optimum Patient Care Research Database, individuals aged 20 years or younger after 1st Jan 2000 at date of recorded XLH diagnosis were identified using SNOMED/Read codes, and age-matched to 100 controls. Recording of XLH-related clinical features was summarised, then compared between cases and controls using Chi-squared or Fisher’s exact tests.


261 XLH cases were identified; 99 met inclusion criteria. Of these, 84/99 had at least 1 XLH-related clinical feature recorded in their primary care EHR. Clinical codes for rickets, genu varum and low phosphate were recorded prior to XLH diagnosis in under 20% of cases (median of 1, 1, and 3 years prior, respectively). Rickets, genu varum, low phosphate, nephrocalcinosis and growth delay were significantly more likely to be recorded in cases.


This characterisation of the EHR phenotypes of children and adolescents with XLH may inform future case-finding approaches to expedite diagnosis in primary care.

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