Parathyroid hormone-related protein (PTHrP) can simulate most of the actions of parathyroid hormone (PTH) including increases in bone resorption and distal tubular calcium reabsorption and inhibition of proximal tubular phosphate transport.1 The low serum phosphate in parallel with low circulating PTH is consistent with PTHrP involvement in this case. Whether it can be causative for a serum calcium of 6.24 mmol/L however is a moot point. While the mechanism underlying the patient’s severe hypercalcaemia proposed by the authors is plausible, the evidence provided for PTHrP being at the root cause is not definitive. The significant differences in mRNA and PTHrP protein fragments reported between neoplastic and normal tissue does not inform on its functional status; it could be …
: Hypercalcemia is defined as a serum calcium concentration that is greater than two standard deviations above the normal mean, which in children may vary with age and sex, reflecting changes in the normal physiology at each developmental stage. Hypercalcemic disorders in children may present with hypotonia, poor feeding, vomiting, constipation, abdominal pain, lethargy, polyuria, dehydration, failure to thrive, and seizures. In severe cases renal failure, pancreatitis and reduced consciousness ...
#1Hye Jin Park(DCU: Catholic University of Daegu)H-Index: 6
#2Eun Jin Choi(DCU: Catholic University of Daegu)H-Index: 7
Last. Jin-Kyung Kim(DCU: Catholic University of Daegu)H-Index: 28
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Severe hypercalcemia in children is a rare medical emergency. We present a case of a 15-year-old boy with hypercalcemia (total calcium level, 14.2 mg/dL) with a normal complete blood count, no circulating blasts in the peripheral blood film, and no other signs of acute lymphoblastic leukemia (ALL), including no signs of lymphadenopathy or hepatosplenomegaly. The hypercalcemia was successfully treated with zoledronic acid. As hypercalcemia can be the only presenting symptom of ALL in children, th...
Last. Martin Konrad(Boston Children's Hospital)H-Index: 49
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Idiopathic infantile hypercalcemia (IIH) is characterized by severe hypercalcemia with failure to thrive, vomiting, dehydration, and nephrocalcinosis. Recently, mutations in the vitamin D catabolizing enzyme 25-hydroxyvitamin D3-24-hydroxylase (CYP24A1) were described that lead to increased sensitivity to vitamin D due to accumulation of the active metabolite 1,25-(OH)2D3. In a subgroup of patients who presented in early infancy with renal phosphate wasting and symptomatic hypercalcemia, mutatio...
Malignancy-associated hypercalcemia is a common finding among adult malignancies. However, the incidence of malignancy-induced hypercalcemia associated with germ cell tumor among pediatric patients is very rare. We describe a 9-year-old girl with an ovarian dysgerminoma presenting with chronic constipation and hypercalcemia. We review some of the causes of malignancy-associated hypercalcemia described in literature and treatment strategies. We also recommend considering oncological processes in ...
Cancer cells produce parathyroid hormone-related protein (PTHrP) in the early phase of malignancy development, before hypercalcemia occurs. The relationship between PTHrP and the clinicopathologic features of oral squamous cell carcinoma is poorly understood. We studied 60 patients (43 men, 17 women; mean age, 64.8 ± 11.2 years) with primary oral squamous cell carcinoma, from whom pretreatment biopsy specimens were obtained. We examined the relationship among immunohistochemical PTHrP expression...
: By interacting with a structurally identical receptor, parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP) display a common spectrum of action on the transport of mineral elements in bone and kidney. In vivo, PTH/PTHrP similarly reduce the renal tubular reabsorption of inorganic phosphate (Pi) and increase that of calcium. The hypercalcemic effect of PTHrP is due to an increase in both bone resorption and renal calcium reabsorption, the latter through a sodium-independent...
