There are several names for a relatively rare disease that affects about 1 in every 20,000 people. It is generally referred to by physicians by its acronym, XLH. XLH is a genetric disorder that is passed from one generation to the next, although a spontaneous mutation may occur in a family with no previous family history of XHL. It is carried on the X-chromosome; hence the "X-linked" name. The rest of the name identifies the primary and key sign of XLH, which is a low level of phosphorus in the blood; this is called hypophosphatemia. Another sign, which doesn't always occur or can be mild to severe when it does, is bone disease called rickets where the legs can become knock-kneed or bowed. There are also other genetic bone diseases causing hypophosphatemia which are autosomal -not X-Linked inheritance. While different in subtle ways, these other diseases and XLH can have effects that are very similar.
XLH Network - http://www.xlhnetwork.org
