This study reports the benefits and side effects of conventional treatment,
phosphate and
calcitriol supplementation in patients with heritable
hypophosphatemic rickets and a long-term follow-up, median of 60.9 months. The group is composed of 17 patients (ten girls). Sixteen patients presented with bone
pain and/or
deformities, and in one patient the diagnosis was radiological. All the patients had increased
alkaline phosphatase,
hypophosphatemia, decreased fractional
phosphate tubular reabsorption (TRP) and maximum tubular
phosphate reabsorption/glomerular filtration rate ratio (TPO4/GFR). Ten of 17 patients had
metabolic acidosis, which was corrected only with the conventional treatment.
Potassium citrate was prescribed to the patients who developed
hypercalciuria. Excluding one patient with pulmonary dysfunction, the remaining 16 patients were divided into two groups according to the age at treatment onset (T0): group I (GI) > or =4 years (n =9) and GII <4 years (n =7). GI and GII had similar follow-up periods and treatment protocols. Seven out of nine GI patients underwent
orthopedic surgery, in contrast to none of GII. Anthropometric data results showed that within each group there is no difference in weight and stature z -score at T0 and at the end of the observation (Tf), but, when both groups are compared, GII shows higher z-score for stature at T0 (p <0.05) and at Tf (p <0.05).
Nephrocalcinosis developed in three cases and correlated with
hypercalciuria (p <0.001) and dose of
calcitriol (p =0.03). In conclusion, higher stature z-score is associated with early treatment. A careful protocol is recommended to detect such complications as
nephrocalcinosis. We suggest
potassium citrate for patients with
hypercalciuria to avoid
calcium precipitation.