Sir.—While in my genetics fellowship, I performed isozyme analysis on serum samples from two children with hyperphosphatasia. Both these cases conformed to the criteria suggested in the recent article by Kraut et al.1 These children presented with failure to thrive, which was present in most of the cases reported by Kraut et al. It may be that during failure to thrive (a state of prolonged starvation) there is bone resorption (due to likely inadequate calcium and phosphorus intake) and liver degeneration, resulting in the leakage of alkaline phosphatase into the blood, and that reversal of starvation returns the liver and bone metabolism to normal.
GOLDSTEIN DJ. Failure to Thrive in Children With Hyperphosphatasia. Am J Dis Child. 1986;140(5):408. doi:10.1001/archpedi.1986.02140190018006