scholarly journals Loss‐of‐Function Mutations in the ALPL Gene Presenting with Adult Onset Osteoporosis and Low Serum Concentrations of Total Alkaline Phosphatase

2020 ◽  
Vol 35 (4) ◽  
pp. 657-661 ◽  
Author(s):  
Nerea Alonso ◽  
Beatriz Larraz‐Prieto ◽  
Kathryn Berg ◽  
Zoe Lambert ◽  
Paul Redmond ◽  
...  
2004 ◽  
Vol 62 (4) ◽  
pp. 940-948 ◽  
Author(s):  
Carolina A.M. Kulak ◽  
Victória Z.C. Borba ◽  
John P. Bilezikian ◽  
Carlos E. Silvado ◽  
Luciano de Paola ◽  
...  

The aim of this cross sectional study was to evaluate bone mineral density (BMD) and serum levels of 25-hydroxy vitamin D (25OHD) in a group of patients taking antiepileptic drugs (AED) for a seizure disorder. Between May-2001 and January-2003, we evaluated 58 patients (40 women/18 men), 34.4±6 years old living in Curitiba or in its metropolitan area, on antiepileptic therapy for 2 to 38 years (10 on monotherapy /48 on multiple drugs regime). The group was matched by age, gender, and bone mass index to 29 healthy subjects (20 women/ 9 men); 34.2±5.9 years old. Medical history and physical exam were performed on all subjects with particular information sought about fractures and risks factors for osteoporosis. Blood samples were collected for total serum calcium, albumin, phosphorus, creatinine, total alkaline phosphatase, and liver function tests. BMD of the lumbar spine, femur and forearm was determined by dual energy X-ray absorptiometry (DXA, Hologic QDR 1000). Between February and April-2003, other blood samples were collected to measure 25OHD, intact paratohormone (PTH) and calcium. Unemployment and smoking history were more frequent among patients than among controls (p<0.05). Fifteen patients had a fracture history, all of which occurred during a seizure. The BMD of the lumbar spine (0.975±0. 13 g/cm² vs. 1.058±0.1 g/cm²; p<0.03) and of the total femur (0.930±0.1 g/cm² vs. 0.988±0.12 g/cm²; p<0.02) was lower in patients than in controls. In 63.5% of patients and in 24.1 % of controls a T-score < -1.0 in at least one site was seen. The AED users had higher total alkaline phosphatase and lower 25OHD (p<0.02). No correlations between BMD and 25OHD were found. The use of phenytoin was correlated with a greater incidence of fractures (RR: 2.38). We conclude that patients on chronic use of AED have alterations in bone metabolism characterized in this study by lower BMD of the lumbar spine and total femur and lower serum concentrations of 25OHD.


1969 ◽  
Vol 15 (2) ◽  
pp. 108-123 ◽  
Author(s):  
Roy B Johnson

Abstract A highly sensitive fluorometric method for the assay of total alkaline phosphatase and the detection of its components is described. The commercially available substrate naphthyl AS-MX phosphate, combined in 1 M 2-amino-2-methyl-1-propanol buffer, pH 9.8, is cleaved to the highly fluorescent naphthol AS-MX. Fluorometry requires filters passing 405 mµ primary and 505 mµ secondary. As little as 20 µl. of normal serum per 3 ml. of reaction mixture can be assayed. Alkaline phosphatase components, separated by vertical starch gel (or other methods of) electrophoresis, produce yellow fluorescence under ultraviolet light when incubated at 37° with the same buffer-substrate. After vertical starch gel electrophoresis, all normal serums exhibit at least one component (β-globulin region), but six distinct areas of activity have been located. These correspond to Taswell and Jeffers’ origin, beta-lipoprotein, alpha-2, alpha-beta, and beta (5). Few serums contain all of these; rather there appears to be a correlation between the ones present, their relative activity, and the disease state.


1977 ◽  
Vol 167 (1) ◽  
pp. 281-284 ◽  
Author(s):  
M G Low ◽  
J B Finean

Purified phosphatidylinositol-specific phospholipase C from Staphylococcus aureus released a substantial proportion of the total alkaline phosphatase activity from a wide range of tissues from several mammalian species. Co-purification of the phospholipase C and alkaline phosphatase-releasing activities and the inhibition of both these activities by iso-osmotic salt solutions suggested that the releasing effect was unlikely to be due to a contaminant.


2015 ◽  
Vol 42 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Julia J. Scialla ◽  
Rulan S. Parekh ◽  
Joseph A. Eustace ◽  
Brad C. Astor ◽  
Laura Plantinga ◽  
...  

Background: Abnormalities in mineral homeostasis are ubiquitous in patients on dialysis, and influenced by race. In this study, we determine the race-specific relationship between mineral parameters and mortality in patients initiating hemodialysis. Methods: We measured the levels of fibroblast growth factor 23 (FGF23) and 25-hydroxyvitamin D (25 D) in 184 African American and 327 non-African American hemodialysis patients who enrolled between 1995 and 1998 in the Choices for Healthy Outcomes in Caring for ESRD Study. Serum calcium, phosphorus, parathyroid hormone (PTH) and total alkaline phosphatase levels were averaged from clinical measurements during the first 4.5 months of dialysis. We evaluated the associated prospective risk of mortality using multivariable Cox proportional hazards models stratified by race. Results: PTH and total alkaline phosphatase levels were higher, whereas calcium, phosphorus, FGF23 and 25 D levels were lower in African Americans compared to those of non-African Americans. Higher serum phosphorus and FGF23 levels were associated with greater mortality risk overall; however, phosphorus was only associated with risk among African Americans (HR 5.38, 95% CI 2.14-13.55 for quartile 4 vs. 1), but not among non-African Americans (p-interaction = 0.04). FGF23 was associated with mortality in both groups, but more strongly in African Americans (HR 3.91, 95% CI 1.74-8.82 for quartiles 4 vs. 1; p-interaction = 0.09). Serum calcium, PTH, and 25 D levels were not consistently associated with mortality. The lowest and highest quartiles of total alkaline phosphatase were associated with higher mortality risk, but this did not differ by race (p-interaction = 0.97). Conclusions: Aberrant phosphorus homeostasis, reflected by higher phosphorus and FGF23, may be a risk factor for mortality in patients initiating hemodialysis, particularly among African Americans.


Author(s):  
Annabelle M Warren ◽  
Peter R Ebeling ◽  
Vivian Grill ◽  
Ego Seeman ◽  
Shoshana Sztal-Mazer

Summary Hypophosphatasia (HPP) is a rare and under-recognised genetic defect in bone mineralisation. Patients presenting with fragility fractures may be mistakenly diagnosed as having osteoporosis and prescribed antiresorptive therapy, a treatment which may increase fracture risk. Adult-onset HPPhypophosphatasia was identified in a 40-year-old woman who presented with bilateral atypical femoral fractures after 4 years of denosumab therapy. A low serum alkaline phosphatase (ALP) and increased serum vitamin B6 level signalled the diagnosis, which was later confirmed by identification of two recessive mutations of the ALPL gene. The patient was treated with teriparatide given the unavailability of ALP enzyme-replacement therapy (asfotase alfa). Fracture healing occurred, but impaired mobility persisted. HPP predisposes to atypical femoral fracture (AFF) during antiresorptive therapy; hence, bisphosphonates and denosumab are contraindicated in this condition. Screening patients with fracture or ‘osteoporosis’ to identify a low ALP level is recommended. Learning points Hypophosphatasia (HPP) is a rare and under-recognised cause of bone fragility produced by impaired matrix mineralisation that can be misdiagnosed as a fragility fracture due to age-related bone loss. Antiresorptive therapy is contraindicated in HPP. Low serum alkaline phosphatase (ALP) provides a clue to the diagnosis. Elevated serum vitamin B6 (an ALP substrate) is indicative of HPP, while identification of a mutation in the ALPL gene is confirmatory. Enzyme therapy with recombinant ALP (asfotase alfa) is currently prohibitively costly. Treatment with anabolic bone agents such as teriparatide has been reported, but whether normally mineralized bone is formed requires further study.


Author(s):  
Piotr Daniszewski

To estimate differentiation of activity of total alkaline phosphatase in water of the Barlinek Lake, of the during stagnation time of 2008. Studies upon water revealed that, among the zones analyzed, upper sublittoral layer was characterized by the highest phosphatase activity. From the analysis of seasonal oscillations it follows that activity maximum for alkaline phosphatase, both in water, occurred July 2008.


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