Tissue Alkaline Phosphatase in Hypophosphatasia

Abstract

Hypophosphatasia is an unusual disease of childhood characterized by abnormalities of bone and low alkaline phosphatase activity in the serum. Since the first report by Rathbun,¹ in 1948, a number of additional cases have been recorded. The disease appears to be genetic in origin and is believed to be transmitted through the action of a recessive gene.² Hypophosphatasia does not present a single uniform clinical picture. In a recent review Fraser² classified the disease into three main groups. The first group consists of infants with severe bone deformities in whom the lesions either are present at birth or appear within the first 6 months of life. Many of these infants have convulsive seizures. This infantile form of hypophosphatasia has an unfavorable prognosis, and most of these patients die at an early age as a result of intercurrent infection. The second group of cases of hypophosphatasia is characterized