Fahr syndrome, rare cause of neuropsychiatric manifestations in children: A two cases report

Fahr syndrome is a rare anatomo-clinical entity in pediatrics. Associating calcifications of the basal ganglia with phospho-calcium metabolism disorders, most often resulting in neuropsychiatric symptoms. In our study, the discovery of this syndrome in our two patients was fortuitous thanks to the typical radiological appearance, associated with the clinical picture they initially presented, hence the interest of brain imaging in the diagnosis of this syndrome.

Concerning effective and safe dosages of vitamin D3: mega-analysis of clinically effective studies as a basis for actual evidence

The negative effects of hypovitaminosis D3 and vitamin D3 deficiency in 80% of Russians make eliminating vitamin D deficiency an issue of state concern. Hundreds of effective clinical studies showed realistic opportunities of vitamin D3 to help patients with disorders of carbohydrate and lipid metabolism, high levels of nonspecific inflammation, tuberculosis, and women with a higher risk of complications and pregnancy losses. Vitamin D3 supplements are essential for the prevention and treatment of a wide range of “bone” and “extraosseous” diseases. One of the most important aspects of the clinical uses of vitamin D3 is the dosage and dosage regimen of the vitamin. This paper presents the results of a “mega-analysis” of 3965 clinical studies of vitamin D3 in terms of the effectiveness of different dosages in achieving different clinical outcomes. It was shown that dosages of 2000 IU/day and 4000 IU/day correspond to the peak values of the effectiveness index, regardless of the diagnoses studied (mega-analysis of 420 randomized trials). Some effectiveness in the treatment of rickets, gestational diabetes, calcium metabolism disorders, disorders of bone density and structure, diseases of the musculoskeletal system and connective tissue can be achieved using weekly dosages of 50,000 IU/week (mega-analysis of 196 studies). It has been shown that dosages of 100,000-1,000,000 IU, intended for a single dose once a month, are almost always found only among studies with a negative result (mega-analysis of 368 studies).

The role of calcium metabolism disorders in the formation of different density calculi with calcium oxalate nephrolithiasis

Objective To investigate the relationship between calcium metabolism disorders, stone formation inhibitor levels and stone density in primary and recurrent calcium-oxalate nephrolithiasis.Material and Methods Sixty nine patients with urolithiasis were examined, their average age was 41,4 ± 9,5 years. Two main groups were distinguished: Group 1 – primary calcium-oxalate nephrolithiasis (PN), Group 2 – recurrent calcium-oxalate nephrolithiasis (RN). Then each group was divided into two subgroups – A and B according to stone density: 500–1000 HU and from 1000–1500 HU, respectively. Stone density was determined by computed tomography (CT). PTH (parathormone), PTHrP (parathyroid hormone related protein), vitamin D, total blood calcium (Ca), ionized blood Ca, total blood protein, Ca and urine pH were also examined. After the examination, patients underwent surgical removal of the stones.Results It was found that 41.9% of group 1 and 46.9% of group 2 patients had grade I obesity. Average creatinine level in group 2 was 9.7% higher than in group 1 (p < 0.05). Urea level in both groups was not statistically significantly different. Glomerular filtration rate (GFR) was comparable. Groups 2A and 2B had higher PTHrP values (77.61 and 76.98 pg/mL, respectively) combined with relatively high PTH levels (2A – 4.4 pg/mL and 2B – 5.1 pg/mL), relatively low osteopontin concentration (2A – 0.044 pg/ mL, 2B – 1.106 pg/mL), compared to those in group 1 (p < 0.05). Pairwise unidirectional differences between groups 1A and 2A, 1B and 2B were found to correlate positively with density values: for osteopontin: r = 0.992 (p < 0.05); for vitamin D: r = 0.831 (p < 0.05); for blood Ca2+ ions: r = 0.836 (p < 0.05); for urine pH: r = 0.863 (p < 0.05). There was a negative correlation with the daily concentration of urinary calcium ions with the density of concrements: r = -0.663; p < 0.05. The concentration of osteopontin was significantly higher in Group 1B and 2B patients, and it was significantly lower in patients with stones of < 1000 HU density. Higher values of osteopontin concentration were noted in groups 1B and 2B in relation to groups 1A (p < 0.05) and 2A (p < 0.05). The increase of blood Ca2+ ions in patients in groups 1B and 2B in relation to groups 1A (p < 0.05) and 2A (p < 0.05) was also accompanied by higher values of vitamin D.Conclusion Patients with denser stones showed high values of osteopontin and PTHrP in serum and low values of urinary calcium ions, which may lead to the formation of concrements on the matrix with an organic base. Determination of calcium metabolism makes it possible to predict recurrence of KSD in primary calcium oxalate nephrolithiasis and assess the severity of mineral metabolism disorders in recurrent calcium oxalate nephrolithiasis.

Determining biological variation of serum parathyroid hormone in healthy adults

Introduction: Measurement of parathyroid hormone (PTH) is essential in the investigation and management of calcium metabolism disorders. To assess the significance of any assay result when clinical decision making biological variation (BV) of the measurand must be taken into consideration. The aim of the present study is determining the BV parameters for serum PTH. Materials and methods: Blood samples were taken at weekly intervals from 20 healthy subjects for ten weeks in this prospective BV study. Serum “intact PTH” concentrations were measured with electrochemiluminescence method. Biological variation parameters were estimated using the approach proposed by Fraser. Results: The values of within-subject biological variation (CVI), between-subject biological variation (CVG), analytical variation (CVA), reference change value (RCV) and individuality index (II) for serum PTH were 21.1%, 24.9%, 3.8%, 59.4% and 0.8%, respectively. Within-subject biological variation and CVG were also determined according to gender separately; 18.5% and 24.0%; 26.2% and 18.6% for male and female, respectively. Calculated desirable precision and bias goals were < 10.6% and < 6.3%, respectively. Conclusion: This study may contribute to BV data on serum PTH as it includes a sufficient number of volunteers from both genders over an acceptable period of time. We do not recommend the usage of population-based reference intervals for serum PTH concentrations. Reference change value may be helpful for the evaluation of serial serum PTH results. Nonetheless, evaluation of data according to gender is necessary when setting analytical performance specifications.

Novel mutations associated with inherited human calcium-sensing receptor disorders: A clinical genetic study

Objective Molecular diagnosis is a useful diagnostic tool in calcium metabolism disorders. The calcium-sensing receptor (CaSR) is known to play a central role in the regulation of extracellular calcium homeostasis. We performed clinical, biochemical and genetic characterization of sequence anomalies in this receptor in a cohort of 130 individuals from 82 families with suspected alterations in the CASR gene, one of the largest series described. Methods The CASR gene was screened for mutations by polymerase chain reaction followed by direct Sanger sequencing. Results Presumed CaSR-inactivating mutations were found in 65 patients from 26 families. These patients had hypercalcemia (median: 11.3 mg/dL) but normal or abnormally high parathyroid hormone (PTH) levels (median: 52 pg/mL). On the other hand, presumed CaSR-activating mutations were detected in 17 patients from eight families. These patients had a median serum calcium level of 7.4 mg/dL and hypoparathyroidism (median: PTH 13 pg/mL). Further, common polymorphisms previously associated with high blood ionized calcium levels were found in 27 patients (median calcium: 10.6 mg/dL; median PTH: 65 pg/mL) with no other alterations in CASR. Overall, we found 30 different mutations, of which, 14 have not been previously reported (p.Ala26Ser, p.Cys60Arg, p.Lys119Ile, p.Leu123Met, p.Glu133Val, p.Gly222Glu, p.Phe351Ile, p.Cys542Tyr, p.Cys546Gly, p.Cys677Tyr, p.Ile816Val, p.Ala887Asp, p.Glu934*, p.Pro935_Gln945dup). Conclusions Patients with CASR mutations may not fit the classic clinical pictures of hypercalcemia with hypocalciuria or hypocalcemia with hypercalciuria. Molecular studies are important for confirming the diagnosis and distinguishing it from other entities. Our genetic analysis confirmed CaSR disorders in 82 patients in the study cohort.