Self Assessment Question [FONT="]A 4-year-old child has blue sclera and a history of multiple fractures with minimal trauma. For this disorder, select the serum concentration of calcium (Ca2+) and phosphate (PO4) with which it is most likely to be associated.[/FONT] [FONT="]A. Low PO4, normal Ca[/FONT] [FONT="]B. Low PO4, high Ca[/FONT] [FONT="]C. Normal PO4, low Ca[/FONT] [FONT="]D. Normal PO4, normal Ca[/FONT] [FONT="]E. High PO4, low Ca[/FONT] [FONT="] [/FONT] [FONT="]EXPLANATION: [/FONT] [FONT="]Osteogenesis imperfecta (blue sclera, easily broken bones with minimal trauma) is transmitted as an autosomal recessive (severe form) or, more commonly, autosomal dominant (milder form) disorder. The basic defect is an abnormality in the production and composition of the matrix of bone. Serum calcium and phosphate concentrations are normal. [/FONT] [FONT="]The answer is D.[/FONT]