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Is it Vitamin D deficient rickets, X-linked hypophosphatemic rickets, or Vitamin D dependent rickets? The mother of an 18 month old African-American boy expressed concern during a routine health supervision visit that her son had not begun to walk. He had been breastfed through 9 months of age and since weaning had received very little dairy products or vitamin D. His weight was 9.8kg (<5th percentile) and he had bilateral wrist enlargement, lower limb bowing and frontal bossing. Laboratory studies demonstrated decreased phosphorus, decreased calcium, elevated alk phosphate, decreased hydroxyvitamin D, and increased dihydroxyvitamin D. Serum creatinine values were normal. Radiographs of the skeleton with fraying and cupping of the metaphyses, especially in the wrists, and widening of the physes.
What is Vitamin D deficient rickets