08.Februaly.2002

 The patient that we treated with infantile hypophosphatasia was well at age 5-6 years when I last heard about her. She was short for her age but otherwise without significant complications. I think the useful information from the article is for the management of high calcium levels...we tried a number of ways to treat it in our patient and eventually were able to treat it by slowing down bone resorption. I would think (as we mentioned in the article) of using bisphosphonates to control the hypercalcemia and slow the resorption of bone if I had a patient with that disease now...there is so much more experience with those medicines now and they are very effective at blocking osteoclast activity. As far as treatment of the disease, we used the hydrochlorothiazide to reduce the urine calcium which was causing problems in her kidney and were hoping that we could get improved mineralization in her bones...given that our experience was in one child only, we were unable to conclude whether our treatment made any difference in the mineralization of her bones. We did see significant improvement however. I think having your son's doctors talk with bone experts about how to improve mineralization in this disease would be the best thing...it may be that bisphosphonates are helpful; I've also seen information about statins being helpful in improving bone mineralization in adults with other diseases. I think there is a role for the hydrochlorothiazide but maybe only for the hypercalciuria...I did review a manuscript several years ago for Journal of Pediatrics in which a patient with the disease did not respond to hydrochlorothiazide...I'm not sure if the paper was published or not. If you have specific questions, i'd be happy to try to answer them. 

Sincerely, John Barcia, MD (Pediatric Nephrology, University of Virginia)