Familial hypophosphataemic rickets affecting a father and his two daughters: a case report.

BACKGROUND

Hypophosphataemic rickets (HR) is a rare cause of short stature associated with limb deformities.

OBJECTIVE

To report the clinical and laboratory features of HR in two siblings and their father.

METHODS

Following the diagnosis of HR in a 4-year-old girl, her siblings and parents were screened using clinical, laboratory, and radiological parameters.

RESULTS

Short stature, lower limb deformities, frontal bossing and hypophosphataemia were present in all three patients. Serum alkaline phosphatase (ALP) was markedly elevated in both siblings who were aged two and 11 years but only minimally raised in their 43-year-old father. While spontaneous mutation is the presumed aetiology in the father, X linked dominant inheritance is the likely cause in both daughters.

CONCLUSIONS

Hypophosphataemic rickets should be considered in the differential diagnosis of short stature associated with limb deformities regardless of a family history of HR. Serum ALP may not be remarkably elevated when the diagnosis is made in adulthood.