Diagnosis Of Hypophosphatemic Rickets Research Articles

Misdiagnosed metabolic bone abnormality: a case report

BackgroundMetabolic bone disease causes significant morbidity and mortality, especially when misdiagnosed. With genetic testing, multiple disease pathologies can be analyzed.Case presentationA 5-year and 9-month-old otherwise healthy Yemeni girl presented to her Yemen physician for evaluation of inward bending of her right knee and short stature. After extensive medical testing, she was given a diagnosis of hypophosphatemic rickets and growth hormone deficiency and started on treatment. Despite appropriate treatment, however, her condition continued to progress, prompting her family to pursue additional workup including genetic testing outside of Yemen. Genetic testing ultimately revealed a variation of unknown significance associated with amelogenesis imperfecta.ConclusionsHypophosphatemic rickets secondary to renal tubular acidosis was the working diagnosis. However, the patient’s condition did not improve. Further genetic testing revealed a variation of unknown significance associated with amelogenesis imperfecta. We aim to present this case, provide an overview of the causes, and diagnostic metabolic bone health evaluation.

Value of serum fibroblast growth factor 23 in diagnosis of hypophosphatemic rickets in children

To study the value of serum fibroblast growth factor 23 (FGF23) in the diagnosis of hypophosphatemic rickets in children. A total of 28 children who were diagnosed with hypophosphatemic rickets in Children's Hospital of Nanjing Medical University from January 2016 to June 2021 were included as the rickets group. Forty healthy children, matched for sex and age, who attended the Department of Child Healthcare of the hospital were included as the healthy control group. The serum level of FGF23 was compared between the two groups, and the correlations of the serum FGF23 level with clinical characteristics and laboratory test results were analyzed. The value of serum FGF23 in the diagnosis of hypophosphatemic rickets was assessed. The rickets group had a significantly higher serum level of FGF23 than the healthy control group (P<0.05). In the rickets group, the serum FGF23 level was positively correlated with the serum alkaline phosphatase level (rs=0.38, P<0.05) and was negatively correlated with maximum renal tubular phosphorus uptake/glomerular filtration rate (rs=-0.64, P<0.05), while it was not correlated with age, height Z-score, sex, and parathyroid hormone (P>0.05). Serum FGF23 had a sensitivity of 0.821, a specificity of 0.925, an optimal cut-off value of 55.77 pg/mL, and an area under the curve of 0.874 in the diagnosis of hypophosphatemic rickets (P<0.05). Serum FGF23 is of valuable in the diagnosis of hypophosphatemic rickets in children, which providing a theoretical basis for early diagnosis of this disease in clinical practice.

Difficulties in the management of hypophosphatemic rickets in adulthood

Introduction. The therapeutic management of hypophosphatemic rickets in adulthood aims to reduce bone pain, the extent of osteomalacia and improve fracture healing and surgical recovery, but clinicians need to stay alert as potential risks can sometimes exceed the benefits of treatment.Case report. We present the case of a 25 year old male patient who was admitted in our department for evaluation presenting severe bone pain. From his medical history we mention that he was diagnosed with rickets at the age of 3 years and received treatment with vitamin D and calcium with no clinical response. A corrective surgery for femur valgus was performed two years later. Because he received high doses of vitamin D without improvement of symptoms the suspicion of vitamin D-resistant rickets was raised at the age of 12 years and treatment with calcitriol 3 tb/day was started with a decline of alkaline phosphatase level from 1144 to 509 UI/l. Two years ago he was diagnosed with renal microlitiasis and left tibial fracture. At present admission he presented with disarmonic short stature, H=149.4 cm (-4.14 SD), W=59 kg, macrocephaly, dental dystrophy and leg bowing. He was under chronic treatment with active vitamin D analog 2 tb/day. Laboratory tests revealed low phosphate (P=2 mg/dl), low 25-OH-vitamin D (19 ng/ml) and 1,25-(OH)2-vitamin D (13.2 pg/ml), normal serum and urinary calcium, normal PTH, high beta crosslaps. In order to diagnose hypophosphatemic rickets, serum FGF23 analysis was performed and it was elevated , but the genetic testing for hypophosphatemic rickets was not available. Because the patient had severe bone pain, a tibial fracture and intented to perform a corrective osteotomy we decided to start medical treatment with elemental phosphorus for 9-12 months, at least 3-6 months before surgery with strict monitoring of serum and urinary calcium and phosphate level, creatinine, alkaline phosphatase and serum PTH.Conclusion. The key point of the case is the late diagnosis of hypophosphatemic rickets and the challenge in treating our patient in order to minimize the risks of combined treatment with calcitriol and phosphorus giving the fact that he was already diagnosed with nephromicrolitiasis.

X-linked hypophosphatemic rickets: Case report

X-linked hypophosphatemic rickets (XLHR) is a dominant inherited disease caused by isolated renal phosphate wasting and impairment of vitamin D activation. We present a girl with X-linked hypophosphatemic rickets (XLHR) as a consequence of de novo mutation in the PHEX gene. A 2.2-year-old girl presented with prominent lower limb rachitic deformity, waddling gait and disproportionate short stature (79 cm, < P5; -1,85 SD). On the basis of hypophosphatemia, hyperphosphaturia, high serum level of alkaline phosphatase, normal calcemia, 25(OH)D and PTH, as well as characteristic clinical and X-ray findings, diagnosis of hypophosphatemic rickets (HR) was made. Normal calciuria and absence of other renal tubular disorders indicated HR as a consequence of isolated hyperphosphaturia. The treatment (phosphate 55 mg/kg and calcitriol 35 ng/kg per day), introduced 15 month ago, resulted in a stable normalization of alkaline phosphatase and phosphorus serum levels (with intact calcemia and calciuria), disappearance of X-ray signs of the active rickets and improvement of the child's longitudinal growth (0.6 cm per month). Subsequently, by detection of already known mutation in the PHEX gene: c.1735G>A (p.G579R) (exon 17), XLHR was diagnosed. Analysis of the parental PHEX gene did not show the abnormality, which indicated that the child's XLHR was caused by de novo mutation of this gene. Identification of genetic defects is exceptionally significant for diagnosis and differential diagnosis of hereditary HR.