Related Experiment Videos
Hyperphosphatemia in infantile hypophosphatasia: implications for carrier diagnosis and screening
B N Chodirker1, J A Evans, L E Seargeant
1Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Canada.
Insights
Infantile hypophosphatasia (HOPS) carriers show decreased alkaline phosphatase and increased urinary phosphoethanolamine. New findings reveal relative hyperphosphatemia, aiding in developing screening models for this rare bone disorder.
Area of Science:
- Biochemistry
- Genetics
- Metabolic Bone Disorders
Background:
- Infantile hypophosphatasia (HOPS) is a severe autosomal recessive metabolic bone disorder.
- Obligate carriers of HOPS are individuals who have a high probability of carrying the gene for the disorder but may not exhibit severe symptoms.
- Understanding carrier status is crucial for genetic counseling and early detection in at-risk populations.
Purpose of the Study:
- To identify and characterize biochemical markers in obligate carriers of infantile hypophosphatasia (HOPS).
- To investigate the presence of relative hyperphosphatemia in HOPS carriers.
- To develop diagnostic and screening models for HOPS carriers within a high-risk population.
Main Methods:
- Study involved 20 obligate carriers of HOPS and 36 controls.
- Biochemical analyses included serum alkaline phosphatase activity, serum phosphate levels, and urinary phosphoethanolamine excretion.
- Logistic regression analysis was employed to create diagnostic and screening models.
Main Results:
- HOPS carriers confirmed to have decreased serum alkaline phosphatase activity and increased urinary phosphoethanolamine excretion.
- Relative hyperphosphatemia was observed for the first time in HOPS carriers.
- A screening model utilizing serum alkaline phosphatase activity and serum phosphate levels proved most effective.
Conclusions:
- Biochemical profiles of HOPS carriers include specific alterations in alkaline phosphatase, phosphate, and phosphoethanolamine.
- The identification of relative hyperphosphatemia offers a new potential diagnostic indicator.
- A practical screening model based on serum alkaline phosphatase and phosphate levels can aid in identifying HOPS carriers in populations at risk.
Abstract:
Twenty obligate carriers of infantile hypophosphatasia (HOPS), a severe autosomal recessive metabolic bone disorder, were studied and compared with 36 controls. Decreased serum alkaline phosphatase activity and increased urinary phosphoethanolamine excretion were confirmed in the HOPS carriers. Relative hyperphosphatemia was documented for the first time in the carriers. Logistic regression analysis was used to develop models for the diagnosis of and screening for HOPS carriers in the high-risk population of Manitoba Mennonites. Models based on serum alkaline phosphatase activity and on serum phosphate levels with or without urinary phosphoethanolamine excretion were used for diagnostic purposes. A model based on serum alkaline phosphatase activity and on the serum phosphate level was the most suitable for screening.