This is the face of a very fair skinned boy who had decreased vision in both eyes since birth. On slit lamp examination, he had iris transillumination.
1. What is the diagnosis?
2. What is the most likely cause of the decreased vision?
3. What ocular examination findings may this child have?
4. What enzyme deficiency may be responsible for these clinical features?
5. What potentially life threatening conditions may be associated with this child's oculocutaneous findings?