Paget's disease of bone--a clinical and genetic study.

An unselected series of 285 patients with Paget's disease of bone has been studied, of whom 54% were male and 46% female. The youngest was aged 25 years at diagnosis and the oldest 95. Of the patients 109 (38-2%) had never suffered serious symptoms. These diagnosed cases certainly represent only a small proportion, perhaps 10-15%, of all those with Paget's disease in the community from which they came. Few of the undiagnosed cases are likely to be suffering from serious symptoms or complications so it is apparent that the majority (probably over 80 or 90%) of those with the pathological state are relatively untroubled by their disease. The most common complication (8-8%) was pathological fracture. The fracture involved the shaft of the femur in 62% occurring in this section of the bone almost seven times more frequently in the patients with Paget's disease than in the general population. Because of the large number of undiagnosed cases in the community, the true incidence of pathological fracture and of sarcoma of bone in all patients with Paget's disease is probably only 1% and 0-1% respectively. Simultaneous estimates of the serum alkaline phosphatase and ESR were made in 128 of the patients. It was shown that the ESR is valueless as a measure of activity or extent of the disease. In many patients the level of the serum alkaline phosphatase changed very little over periods of several years. A history of the disease in one or more close relatives was found in three families, a lower incidence than was expected from previously recorded studies. The ABO blood groups were determined in 215 of the patients; 50% were of group A compared with 46% in a control group. The difference in distribution of blood groups in the two series of subjects is small and well within chance limits. The secretor status of 138 patients was investigated; 77% were secretors. This is similar to the proportion in control series. There is evidence to suggest that the degree of severity of Paget's disease does not vary, once it has developed in any particular individual, and that the more severe and extensive forms may have a stronger genetic basis.