Allergic to the sun, two-year-old Charlie needs a bone-marrow transplant

Two-year-old Charlie Lock likes to look out her window. She’s too young to understand that the world beyond the tinted glass is forbidden to her.
One year ago, Charlie was diagnosed with erythropoietic protoporphyria (EPP) — a genetic disease that is sometimes described as an allergy to the sun.
Even small amounts of ultraviolet light cause the toddler’s skin to burn, blister and swell. But it’s the invisible damage — the accumulation of porphyrins in her liver &mda