ASPHO October, 2009 Case Quiz Guy Young, MD This is the most memorable case from my fellowship. I saw this child as a second-year fellow, and I have no doubt that this case influenced my interest in the field of coagulation. An 8-year-old dysmorphic (see Figure 1), wheelchair-bound male presented to the hematology clinic for a prolonged partial thromboplastin time (PTT; the PT was normal), which was drawn as part of a preoperative evaluation for tendon-release surgery. He was born after a full-term pregnancy and was noted to be developmentally delayed by 6 months. Dysmorphic features include a prominent jaw, almond-shaped eyes with squint, buttock fat pads, and kyphoscoliosis. In addition, he had a protein-losing enteropathy and intermittently elevated transaminases. In the past, he had multiple episodes of transient unresponsiveness with transient hemiplegia lasting from a few minutes to several hours and always with complete recovery. He had no prior history of bleeding (i.e., no mucocutaneous bleeding symptoms and no bleeding with several minor surgical procedures). As far as his parents were aware, this was the first time he had coagulation tests performed. There is no family history of bleeding. The ethnicity of the family is French, Native American, and German. The patient had been evaluated in three large, academic medical centers in the Northeast, but no diagnosis for his underlying condition could be identified. Figure 1. *photo used with permission 1. Regarding the prolonged PTT, which of the following would be the most appropriate next step? Repeat the PTT. Perform mixing studies. Order factor assays of the intrinsic pathway. All of the above.