Q. A 23-year-old male presents to your clinic with scleral icterus (see image). He reports that he has been experiencing yellowing of his skin and eyes for the past week and has noticed that his urine has been dark in color. The patient denies any known sick contacts or recent travel. He also denies any other symptoms such as abdominal pain, nausea, vomiting, or fever. The patient has no significant medical history, and is not currently taking any medications. He also reports that he has never been hospitalized or had any surgeries in the past. The patient does not smoke tobacco or drink alcohol. On physical examination, he is alert and oriented, and his vital signs are within normal limits. His sclera appear yellow bilaterally, otherwise the rest of his physical examination is unremarkable, including his abdomen and liver. You order blood work, and his complete blood count and metabolic panel are within normal limits. His bilirubin level is 2.2 mg/dL, and his liver enzymes are normal. Additionally, his alkaline phosphatase level is 80 IU/L, and prothrombin time and international normalized ratio are normal. Based on the information you have at this point in time, which of the following is the LEAST likely diagnosis?