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Hereditary hyperphosphatasia: 20 year follow‐up and response to disodium etidronate
Author(s) -
Singer Frank,
Siris Ethel,
Shane Elizabeth,
Dempster David,
Lindsay Robert,
Parisien May
Publication year - 1994
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1002/jbmr.5650090519
Subject(s) - osteoid , cancellous bone , medicine , iliac crest , biopsy , osteomalacia , endocrinology , bone remodeling , bone disease , paget's disease of bone , hydroxyproline , pathology , surgery , vitamin d and neurology , disease , osteoporosis
We provide a 20 year follow‐up of a family with three siblings affected by hereditary hyperphosphatasia (HH). An iliac crest bone biopsy was performed on one of the siblings following double‐tetracycline labeling, with results reported quantitatively in a standard histomorphometric format. Biochemical parameters of disease activity were monitored in the patient before and after treatment with oral etidronate disodium, 20 mg/kg/day taken for 5 weeks. Biochemical evidence of intense disease activity continued 20 years after the initial diagnosis of HH in the sibling studied. His bone biopsy specimen also revealed extremely high bone turnover but low cancellous bone volume and osteoclasts unlike those found in Paget's disease. Treatment with etidronate disodium resulted in a temporary 40% reduction in serum alkaline phosphatase and 24 h urine hydroxyproline excretion, with reduction in serum osteocalcin from two times the upper limit of normal to a subnormal level. We conclude that disease activity in HH can continue unabated for two decades. Our bone biopsy finding of low cancellous bone volume, the consistent lack of pagetic‐looking osteoclasts in our and other studies, plus the clinical features of HH (childhood onset and extremely diffuse disease with gross skeletal deformation) serve to distinguish HH from Paget's disease. Bisphosphonates may be of value in treating HH.