DEXA bone densitometry measurements in adults with X-linked hypophosphatemia

Bone mineral densities in adults with X-linked hypophosphatemia are variable, and while most are reportedly normal some can be very high. Eighteen patients with adult X-linked hypophosphatemia underwent bone mineral determinations of the lumbar spine and femoral neck with dual energy x-ray absorptiometry (DEXA). Most of them were on various treatment regimens. Ten of 18 patients (55%) had spinal bone mineral densities that were greater than two standard deviations above the age-matched mean, and 3 of 11 patients (27%) had bone mineral densities of the femoral neck in excess of two standard deviations. Eight patients (median age 41.5 years) were followed serially for 24 to 42 months, and they exhibited a spinal bone loss of 0.019 gm/cm2/year.