A 7-year-old boy has demineralized bones with pseudofractures. Physiologic doses of vitamin D do not result in improvement. Which of the following is most likely to be associated with this syndrome?

Vitamin D-resistant rickets is a familial disorder, with an X-linked recessive pattern, treated with pharmacologic doses of vitamin D. Half the affected individuals have alopecia, and this tends to correlate with severity.Rickets and osteomalacia are characterized by impaired mineralization of bone. Osteoporosis is a disorder with a diminished amount of normally mineralized bone.