Clinical Presentation, Diagnosis, and Genetic Characteristics of Patients with Hypophosphatemic Rickets

Authors : Yasemin Denkboy Ongen, Şehime G Temel, Ömer Tarım, Şebnem Özemri Sağ, Erdal Eren
Pages : 193-200
Doi:10.32708/uutfd.1653471
View : 96 | Download : 106
Publication Date : 2025-08-28
Article Type : Research Paper
Abstract :Phosphate plays an essential role in bone mineralization. Hypophosphatemic rickets (HR) is a rare phosphate-wasting disorder that leads to rickets, which may be FGF23-dependent or independent. In this study, we aimed to evaluate the clinical features of HR patients with genotypic and phenotypic features. This study included 32 children. The suspected gene was primarily studied in cases meeting the clinical diagnosis. Variants were evaluated according to ACMG criteria. All HR patients\\\' median ages at the onset of complaints and diagnosis were 1.5 and 5 years, respectively (p<0.001). The most common complaint is bowlegs. At the time of diagnosis, calcium was 9.70 mg/dl; phosphorus was 2.68±0.64 mg/dl; ALP was 530±245 u/l, PTH was 58.70 ng/l, tubular phosphate reabsorption was 74±17%, and TmP/GFR was 2.58±1.15. Five of 32 patients were diagnosed with McCune-Albright syndrome, and two patients were followed as HR secondary to chemotherapy. Variants of the PHEX gene were identified in 15 cases (X-linked HR). In X-linked HR patients, no statistically significant difference was found between the age of presentation and diagnosis. Diagnostic delay was observed in infantile hypercalcemia type 2 and hereditary HR with hypercalciuria patients who were followed with nephrocalcinosis from an early age. In conclusion, HR is rare, and patients with bowlegs, short stature, kidney stones, hypophosphatemia, and renal phosphate wasting should be classified as FGF-23 dependent or FGF-23 independent of initiating treatment as soon as possible. Delayed diagnosis is common in cases of nephrocalcinosis, so measurement of calcium and phosphate levels should be standard for these patients.
Keywords : Hipofosfatemik raşitizm, McCune Albright Sendromu, PHEX, SLC34A3, SLC34A1

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