[I'm happy to re-direct (May 9, 1997) this intriguing note regarding a different sort of Familial Hypophosphatemic Rickets, which should be of some interest to those of our F-HYPDRR mailing list members, as well as any interested browsers from the greater Internet, who are not sure where their syndrome came from --
this looks like a good opportunity to see whether any of us can help in the understanding of and further research into genes that are important in bone growth and development but are not on the X chromosome -- LW]
[A research scientist is] interested in finding out if anyone in the group [or on the greater Internet reading this link] has a family history consistent with an autosomal dominant mode of inheritence. Most people with VDRR have an X-linked dominant mode of inheritence (An affected man passes the disease to all of his daughters, but none of his sons. Each of an affected women's children has a 50:50 chance of inheriting the disease.) For an autosomal dominant mode of transmission children from both affected men and affected women have a 50:50 chance of inheriting the disease. To make matters more complicated, we have documented instances in the autosomal dominant condition (1) in which people who have the altered gene are "carriers" (ie they don't have symptoms, but pass the disease to their children). We have documented several instances where women don't get problems until age 14-45 and we have documented 2 instances in which boys with rickets "grew out of it".
The only way to prove that a disease is not X-linked is to show evidence of a male to male transmission (a boy inheriting the disease from his father).
[This researcher's] suspicion is that some of the "sporadic" patients may have ADHR. Does anyone know of a family in which there is a male to male transmission? If anyone in the group [or anyone browsing in these Vitamin D Metabolism and Familial Rickets pages] knows about a family, please email me, Larry.Winger@ncl.ac.uk directly and I'll be happy to pass your message on to the researcher concerned.
1. Econs, M.J., McEnery, P.T. Autosomal dominant hypophosphatemic rickets/osteomalacia: Clinical characterization of a novel renal phosphate wasting disorder. J Clin Endocrinol Metab. 82:674-681,1997.