Mutations of the tissue non-specific alkaline phosphatase gene (TNAP) causing a non-lethal case of perinatal hypophosphatasia

arthritis found that erosions were predated by persistent scintigraphic activity in affected joints [5]. Of note, however, almost all finger joints that eroded were active on clinical examination. The sensitivity of clinical examination was inferior to scintigraphy in the foot joints, but as analysis was by joint rather than by patient and as the scintigraphic score was derived from multiple BS, the implications for routine clinical practice are not clear.