Hypophosphatasia Diagnosis and Management

Initial Evaluation

The American Academy of Pediatrics and the National Institute of Health recommend checking parathyroid hormone (PTH) and 25(OH) vitamin D levels to exclude other metabolic bone disorders in patients with low alkaline phosphatase (ALP) 1
A comprehensive dental history, including any history of premature loss of deciduous teeth, dental abscesses, or periodontal disease, is essential for diagnosing hypophosphatasia (HPP) 1
Growth parameters, such as height, weight, and growth velocity, should be documented in patients with low ALP 1
Functional status, including level of physical function and disability, should be assessed in patients with low ALP 1

A physical examination should include an assessment of lower limb alignment, spine examination for lordosis, kyphosis, or scoliosis, and joint assessment for enthesopathies, osteoarthritis, and range of motion 1
A dental examination should be referred for comprehensive evaluation 1

X-linked hypophosphatemia (XLH) presents with low phosphate and elevated ALP, which is the opposite biochemical pattern of hypophosphatasia (HPP) 1, 2, 3

Clinical monitoring every 6 months, including height, weight, BMI, and blood pressure, is recommended for adolescents with HPP 1
Biochemical monitoring, including ALP, calcium, phosphate, creatinine, PTH, and 25(OH) vitamin D, is essential for managing HPP 1
Dental visits twice yearly are recommended after tooth eruption to prevent and treat infections in patients with HPP 1
Radiographic assessment, including standardized anterior-posterior standing long leg radiographs, should be considered if bone pain develops or deformities worsen 1

Dental care optimization with experienced dentists familiar with HPP is crucial for managing the condition 1

X-linked hypophosphatemia (XLH) presents with low phosphate and elevated ALP, which is the opposite biochemical pattern of HPP, requiring phosphate supplementation and active vitamin D, as recommended by the National Institute of Health, with a strength of evidence level of high 4, 5, 6, 7

There is an inverse correlation between ALP levels and serum calcium, pyridoxal phosphate (PLP), and urinary phosphoethanolamine (PEA), with mutation carriers showing slightly lower ALP, higher PLP and PEA, and mildly increased serum phosphate, according to the Endocrine Society, with a strength of evidence level of moderate 4, 5